Bendix ADB22X, ADB22X-V Air Disc Brakes. SERVICE MANUAL (2013)

Bendix^® ADB22X^™, ADB22X-V^™ Air Disc Brakes

Section one: Air disc brake Overview

Sections in this Document

Section

Page

1.1 DESCRIPTION

Overview

1-5

Bendix^® ADB22X^™ and ADB22X-V^™ Air Disc Brakes

Preventive Maintenance and

(ADB) use a floating caliper design to provide foundation

Wheel-on Inspections

6-8

braking on all axles of heavy commercial vehicles, buses

Troubleshooting Flowchart

and trailers. Bendix Air Disc Brakes provide safety and

Wheel-off Maintenance Inspections .

10-15

performance as well as ease of service.

Maintenance Kits and Procedures

16-37

The ADB22X disc brakes mount to the axle's anchor plate

Full Index - see Page 38

(torque plate) using fasteners that are installed parallel

to the axle, while the anchor-plate fasteners used for the

Bendix^® ADB22X-V^™ air disc brakes install at right angles

1.2 Air Disc Brake Identification

to the axle.

Locate the identification label near the guide pin housing.

See below for information about the label fields used.

Available with or without a combination spring brake unit,

these brakes may also include optional wear sensors and

wear diagnostic equipment.

Figure 2 - Typical part number label location

Bendix Part Number

Serial No.

Customer Part Number

Figure 3 - part number label information

Section One

Section

Page

1.1

Description

Figure 1 - Bendix^® ADB22X^™ Air disc Brakes

1.2

Air Disc Brake Identification

1.3

Rotor Identification

1.4

Wear Sensor Identification

1.5

Operation

1.5.1

Brake Release and Adjustment

generAl SAFety guiDelineS

WARNING: Not all wheels and valve stems

wArning! PleASe reAD AnD

are compatible with Bendix Air Disc Brakes. Use

Follow theSe inStructionS

only wheels and valve stems approved by the

to AVoiD PerSonAl inJury or DeAth:

vehicle manufacturer to avoid the risk of valve

stem shear and other compatibility issues.

when working on or around a vehicle, the following

guidelines should be observed At All tiMeS:

▲ Park the vehicle on a level surface, apply the parking

WARNING: Avoid creating

brakes and always block the wheels. Always wear

dust. Possible cancer and lung

personal protection equipment.

disease hazard.

▲ Stop the engine and remove the ignition key when

working under or around the vehicle. when working

While Bendix Spicer Foundation Brake LLC does not

in the engine compartment, the engine should be shut

offer asbestos brake linings, the long-term affects of

off and the ignition key should be removed. where

some non-asbestos fibers have not been determined.

circumstances require that the engine be in operation,

Current OSHA Regulations cover exposure levels to

eXtreMe cAution should be used to prevent personal

some components of non-asbestos linings, but not

injury resulting from contact with moving, rotating,

all. The following precautions must be used when

leaking, heated or electrically-charged components.

handling these materials.

▲ Do not attempt to install, remove, disassemble or

•

Avoid creating dust. Compressed air or dry

assemble a component until you have read, and

thoroughly understand, the recommended procedures.

brushing must never be used for cleaning brake

use only the proper tools and observe all precautions

assemblies or the work area.

pertaining to use of those tools.

•

Bendix recommends that workers doing brake

▲ if the work is being performed on the vehicle’s air brake

work must take steps to minimize exposure

system, or any auxiliary pressurized air systems, make

to airborne brake lining particles. Proper

certain to drain the air pressure from all reservoirs

procedures to reduce exposure include working

before beginning Any work on the vehicle. if the vehicle

in a well-ventilated area, segregation of areas

is equipped with a Bendix^® AD-iS^® air dryer system, a

where brake work is done, use of local filtered

Bendix^® DrM^™ dryer reservoir module, or a Bendix^®

ventilation systems or use of enclosed cells with

AD-9si^® air dryer, be sure to drain the purge reservoir.

filtered vacuums. Respirators approved by the

▲ Following the vehicle manufacturer’s recommended

Mine Safety and Health Administration (MSHA)

procedures, deactivate the electrical system in a manner

or National Institute for Occupational Safety and

that safely removes all electrical power from the vehicle.

Health (NIOSH) should be worn at all times during

▲ never exceed manufacturer’s recommended pressures.

brake servicing.

▲ never connect or disconnect a hose or line containing

•

Workers must wash before eating, drinking or

pressure; it may whip. never remove a component or

smoking; shower after working, and should not

plug unless you are certain all system pressure has

wear work clothes home. Work clothes should

been depleted.

be vacuumed and laundered separately without

▲ use only genuine Bendix^® brand replacement parts,

shaking.

components and kits. replacement hardware, tubing,

hose, fittings, etc. must be of equivalent size, type

•

OSHA Regulations regarding testing, disposal

and strength as original equipment and be designed

of waste and methods of reducing exposure

specifically for such applications and systems.

for asbestos are set forth in 29 Code of Federal

Regulations §1910.001. These Regulations

▲ components with stripped threads or damaged parts

provide valuable information which can be utilized

should be replaced rather than repaired. Do not

attempt repairs requiring machining or welding unless

to reduce exposure to airborne particles.

specifically stated and approved by the vehicle and

•

Material Safety Data Sheets on this product, as

component manufacturer.

required by OSHA, are available from Bendix.

▲ Prior to returning the vehicle to service, make certain all

Call 1-800-247-2725 and speak to the Tech Team

components and systems are restored to their proper

or e-mail techteam@bendix.com

operating condition.

▲ For vehicles with Automatic traction control (Atc),

the Atc function must be disabled (Atc indicator

lamp should be on) prior to performing any vehicle

maintenance where one or more wheels on a drive axle

are lifted off the ground and moving.

▲ the power MuSt be temporarily disconnected

from the radar sensor whenever any tests uSing A

DynAMoMeter are conducted on a Bendix^® wingman^®

Advanced^™-equipped vehicle.

▲ you should consult the vehicle manufacturer's

operating and service manuals, and any related

literature, in conjunction with the guidelines above.

1.3 Rotor Identification

1.5 Operation

See Figure 4 to help you identify which type of rotor is used

Bendix air disc brakes convert air pressure into braking

on the axle being inspected. Note that the maintenance

force.

(See Figure 6.) When the vehicle brakes are

inspection procedure will depend on the type of rotor

applied, air enters the service brake chamber through

installed.

the supply port, applying pressure within the diaphragm.

The pressure expands the diaphragm — applying force

to, and moving, the pressure plate and push rod forward.

The push rod acts against a cup in the internal lever which

pivots on an eccentric bearing moving the bridge. Moving

against a return spring, the bridge transfers the motion to

two threaded tubes and tappets, which move the inner

brake pad. The inner brake pad (from its normal position

of having a running clearance between it and the rotor)

moves into contact with the brake rotor. Further movement

of the bridge forces the caliper — sliding on two stationary

guide pins — away from the rotor. That, in turn, pulls the

outer brake pad into the rotor. The clamping action of the

brake pads on the rotor applies braking force to the wheel.

Pressure

Supply Port

Service Brake

Plate

Chamber

Inner Brake Pad

Push Rod

Lever

Outer Brake

Pad

Return Spring

Figure 4 - rotor identification

CAUTION: Rotors may not be mixed on a single axle:

axles are only permitted to have all conventional or all

splined disc rotors.

1.4 Wear Sensor Identification

Diaphragm

See Figure 5 for the electronic wear sensor that may be

Bridge

Rotor

present.

Eccentric Bearing

104

FIGURE 6 - cross-section view showing BRAKE

Cable Protection

operation

101

Plate

Sensor

1.5.1 Brake Release and Adjustment

105

101

Cable Guide

When the vehicle brakes are released, the air pressure

Sensor

(2 alternate

in the service brake chamber is exhausted and the return

designs used)

springs in the chamber and the bridge return the air disc

brake to a neutral, non-braked position. To maintain the

running clearance gap between the rotor and the brake

pads over time, the non-braked position is mechanically

103

adjusted by a mechanism in the caliper. The adjustment

Cable to Electrical

mechanism operates automatically whenever the brakes

Supply

are activated, to compensate for rotor and brake pad wear

Sensor

101

and to keep the running clearance constant. During pad

Cable to Electrical Supply . . .

103

or rotor maintenance, the technician manually sets the

Cable Protection Plate

104

system’s initial non-braked position. The total running

Cable Guide (two designs) . . . 105

clearance (the sum of clearances on both sides of the

rotor) should be between 0.024 to 0.043 in. (0.6 to 1.1 mm).

Consult the instruction sheet included with wear

indicator kits for installation information.

Figure 5 - electronic Wear Indicator components

(Wheel turns toward

35 Double-Diaphragm Style

18/1 Spring Brake

fixed pin side of

Spring Brake Chamber

Type A

Type B

Actuator

ADB)

(Fixed pin)

11 Pad Retainer

Pad Retainer Pin

18/2

26 Spring Clip

Service

Actuator

12/2 Pad Holder Spring

(Pad Assembly

consists of

12/1 plus 12/2)

Cap

12/1 Pad

Caliper

Washer

Wheel Rotation

Bolt

Wheel Rotation

Guide

(typically right hand)

(typically left hand)

Brass

Bushing

Cap

Shield

39 Caliper Bolt

Kit

Inner Seal

161

(Drive or

Tappet Bushing

4 Guide Pin

*37 Adjuster

Actuator

Steer)

Hardware

6 Guide Sleeve

Caps (2 styles

13 Tappet

37*

supplied in kits)

and Boot

Shear

Assembly

Adapter

Carrier

Mounting

Hardware

Caliper

U-shaped Rotor

(or Caliper Kit)

Inner Boot

Ring

Bendix^®ADB22X^™

Anchor Plate

Bendix^®

(Rotor Shield for Trailers)

ADB

U-shaped

Rotor

Fasteners

SD-

Drive Hub

SD-2

Bendix^®

ADB22X-V^™

Splined Disc^® Rotor

Anchor Plate

SD-3

Hardware

Carrier

SD-1, -2, -3

Mounting

Hardware

See Section 5.2 for

Splined Disc^® Rotor

(SD)

exploded view of electronic

wear indicator.

Steer Hub

Figure 8 - exploded view - Bendix^® ADB22X^™ and ADB22X-V^™ Air Disc Brakes

Index To Figures 7 & 8

Adjuster Caps

Chain Wheel

Pad Assembly

Spring Brake Actuator (Double-

Adjuster Unit

Cap

Pad Retainer

Diaphragm style)

Bolt

Eccentric Bearing . . .

Pad Retainer Pin

Spring Clip

Brass Bushing

Guide Pins

4, 5

Ring

Tappet and Boot

Bridge

Guide Sleeve

Service Actuator . . . 18/2

Assembly

Caliper

Inner Boot

Shear Adapter

Tappet Bushing

161

Caliper Bolt

39, 40

Inner Seal

Splined Disc Hardware

Threaded Tube

Cap

Lever

. . . . . .SD-1, SD-2 and SD-3

Turning Device

Carrier

2 (A or B)

Pad

12/1

Spring

Washer

Chain

Pad Holder Spring . .

12/2

Spring Brake Actuator . 18/1

Wear Sensor

Section Two: Preventive Maintenance schedule and Wheel-on inspections

2.0 Preventive Maintenance

Regular inspection and maintenance of air disc brake

components is an important part of vehicle maintenance.

Section Two

Section

Page

The maintenance practices outlined here are recommended

2.0

Preventive Maintenance

in addition to all standard industry practices (including

2.1

Brake Pad and Rotor Inspections

7-8

daily pre-trip inspections.) Also, see the vehicle's manual

2.2

Running Clearance Quick Inspection

for recommendations. Keep track of the results of your

maintenance inspections to assist you in determining the

ideal maintenance intervals for the vehicle.

Use the table below for a guide to maintenance interval

planning, however, depending on the particular vehicle's

use, more frequent checks of the components may be

necessary.

Table 1: Inspection Period

(4 to 5 times during the pad lifetime)

About every four (4)

About every three (3) months

* For vehicles with

months for over-the-

for higher-duty applications:

electronic wear

road applications:

At least

indicators, use the

e.g. pick-up & delivery,

once

dash indicator(s)

e.g. line haul, RV,

off-highway, construction,

At the

every

When

open-highway

logger, concrete mixer, dump

very

year

and/or the hand-held

you

coaches, etc.

truck, city transit bus, refuse,

least,

(and at

diagnostic tool to

check

school buses, etc.

every

regularly monitor the

the tire

four (4)

pad

pressures

pad wear.

months

replace-

ment)

See Section 5.2.

Inspections with the wheel mounted (Sections 2.1 - 2.3)

Inspect the pad thickness by

checking the mechanical wear

indicators*. See Section 2.1.

Inspect the running clearances

using the quick inspection

technique. See Section 2.2.

Inspect the visible part of the rotors

for cracks, etc. See Section 2.3.

Inspections with wheel removed (Section 4)

Inspect the pads and entire rotor

surfaces for cracks, etc.

(Bendix^®

splined disc^® rotors: Inspect

retaining hardware and check

torques) See Section 2.3.

Inspect the running clearances and

adjuster operation.

See Sections 2.2 and 4.2.

Inspect the caliper travel.

See Section 4.1.

Inspect the tappet and boot

assemblies. See Section 4.6.

Inspect all caps, hoses, and brake

exterior for damage etc.

Table 1 - Preventive Maintenance Schedule

2.1 brake pad and rotor inspections

Wear Indicator Style A:

Visual checks of the condition of the brake pad/rotor wear

Where both the carrier and caliper have an

can be made without removing the wheels. Where dust

indicator notch.

guards are not used, the top of the pads and part of the

Compare the relative position of two notches cast into

rotor are visible through the opening at the top of the brake.

the carrier and caliper. When the two notches align,

Other visible portions of the rotor can be inspected at the

it is time to schedule a full wheel-removed inspection

same time.

of the pads and rotor.

Unless a vehicle has been stored for some time, the main

rotor surfaces that contact the pads will always appear to

be shiny. Surface rust on these surfaces would indicate a

Notch in the

malfunctioning brake that should be inspected immediately.

caliper

Pads are 1.181 in. (30 mm.) thick when new and must be

replaced when they reach 0.433 in. (11 mm.). Rotors are

1.77 in. (45 mm.) thick when new and must be replaced

Notch in the

when they reach 1.46 in. (37 mm.). See Section 4.3 for

carrier

further inspection criteria.

2.1.1 Electronic Wear Indicators

Use the dash indicator(s) and/or a hand-held diagnostic

When the notches

tool to regularly monitor the pad wear. (See Section 5.2.)

line up, it is time

to schedule an

2.1.2 Mechanical Wear Indicators

inspection of the

See Figure 9 for the location of the mechanical wear

pads and rotor

indicators. There are two types (See Figure 10 for Style A

and Figure 11 for Style B).

Figure 10 - Style A - when both Carrier and caliper

have a cast notch

Quick Visual

Wear Indicator Style B:

Inspection of Pad

Thickness and Rotor

Where only the caliper has an indicator

notch.

Location of Wear

When the notch in the caliper aligns with the front

Indicator Notches

edge of the torque plate, it is time to schedule a full

(Both sides of brake)

wheel-removed inspection of the pads and rotor.

Figure 9 - Location of wear indicators

Notch in

Note: These mechanical wear indicators do

the caliper

not constitute “out-of-service” criteria. These

inspections only show when to schedule a full wheel-

removed inspection of the brake pads and rotor.

No notch

The thicknesses of the pad and rotor will both affect

in the

the wear indicator position at which maintenance is

carrier

actually needed.

When the

Torque

torque plate

plate

edge lines up

with the notch,

it is time to

schedule an

inspection of

the pads and

rotor

Figure 11 - Carrier wear indicator notch and backing

plate alignment

•

For standard Bendix rotors, cracks

No action is needed

running in a radial direction — like

for small cracks

spokes of a wheel (see Area H) — less

spread over the

Area

surface (e.g. Area F)

Area

than 0.06 in. (1.5 mm) deep or wide

are acceptable if they do not reach

either edge (see G). Cracks are only

acceptable if the length of the crack is

less than 75% of dimension “f” (the width

Rotor

of the rotor contact area).

Friction

•

For Bendix Splined Disc rotors, radial

Surface

cracks are only acceptable if they are

Width “f”

less than 0.04 in. (1.0 mm) deep or

wide and if they do not reach either edge

(see G). Crack lengths must be less

than 75% of dimension “f” (the width

Area G

Area J

of the rotor contact area).

Cracks reaching

either edge of the

rotor

are not

In addition, follow the

acceptable

recommendations of the

Circumferential

for either

grooves, as in Area

vehicle manufacturer.

type of

J, are acceptable

Note: Axles should

rotor

if less than 0.06 in.

have either all Bendix

(1.5 mm) deep.

Splined Disc (or all

conventional) rotors.

figure 12 - examples of acceptable and non-acceptable rotor cracks and grooves

2.1.3 Rotor Quick Inspection

See Figure 12. See the various potential rotor conditions

that you may find. See the criteria below for whether the

rotor needs to be replaced and/or scheduled for a full

inspection.

2.2 Running Clearance Quick

Inspection

CAUTION: Follow all safe maintenance practices.

Push/Pull

On level ground, with the wheels chocked and the parking

By Hand

to Check

brake temporarily released, check for movement of the

the Caliper

brake caliper. This small movement, less than 0.08" (2 mm)

Movement

- approximately the thickness of a nickel - in the inboard/

outboard direction indicates that the brake is moving

figure 13 - Caliper running clearance

properly on its guide pins.

(figure does not show wheel)

If the caliper has no movement or appears to move greater

than the distances noted above, a full wheel-removed

inspection will be necessary (See Section 4.1).

Section three: Troubleshooting Procedure Flowchart

Air Disc Brake Inspection

Follow safe maintenance practices,

chock wheels. Engage spring brakes

and cage spring. Release spring

brakes and drain air from system.

Raise axle, spin

the wheel by

hand.

Does

the wheel

turn smoothly?

YES

Check

the

running

YES

spring brake fully/

clearance (4.1)

partially applied?

- OK?

YES

Check

running

adjuster (4.2)

clearance (4.1)

- OK?

YES

Check

Drain air pressure from

Replace caliper/

Pad and rotor

Check

system. Re-start test after

carrier assembly

wear (4.3-4.4)

Adjuster (4.2)

caging spring brakes

(5.3)

- OK?

Check

caliper

YES

guidance (4.5)

- OK?

YES

Replace components

Disc brake OK

Replace caliper/

as needed with

Tightness not due to

carrier assembly

genuine Bendix parts.

air disc brake. See

(5.3)

vehicle manual.

Replace guide pins

(5.6) OR replace

caliper/carrier

assembly (5.3)

Figure 14 - troubleshooting Bendix air disc Brakes

Section four: Wheel-Off maintenance inspections

4.1 Caliper Movement Test

Section Four

CAUTION: Follow all safe maintenance practices.

Section

Page

4.0

Wheel-Off Inspections

Remove the wheel. With the spring brakes released or

4.1

Caliper Movement Test

caged, push the caliper assembly inboard on its guide pins.

4.2

Adjuster Mechanism Inspection . . .

Note: To fully release the spring brakes, assure that the

4.3-4.4 Brake Pads and Rotors

12-14

air system pressure is at least 90 PSI. Using a suitable

4.3

Inspect the Brake Pads

tool (for example a large flat-blade screwdriver), press the

4.4

Inspect the Rotor

13-14

inboard pad (12) away from the tappets. Check that there

4.4.3

Machining (Grinding or Turning) Rotors

is no dirt, etc. in the gap, and clean if necessary. Then use

4.5

Guide Pin Bearing Inspection

14-15

two long-blade feeler gauges to measure over the whole

4.6

Tappet & Boot Assembly Inspection . .

tappet surface the gap between them and the inboard pad

backplate. (See Figure 16.) The gap should be between

0.024 in. (0.6 mm) and 0.043 in. (1.1 mm). If the gap is

within the range given, the test is complete.

4.0 Wheel-off inspections

CAUTION: During these inspections, follow all safe

maintenance practices, including those on page

two of this service manual. Also, follow the vehicle

manufacturer’s recommendations. When working on

foundation brakes, be sure that the vehicle is on level

ground, that the vehicle is parked by other means

than the foundation brakes, and that the wheels are

chocked.

4.0.1 Wheel Removal and Re-Installation

Pull

Caliper

Refer to the vehicle manufacturer’s recommendations for

Inboard

removing the wheel.

Note: When removing the wheel, inspect first to see that

there is no contact between the caliper and axle, vehicle,

Figure 15 - Pull Caliper inboard

chassis sections or carrier, etc. that may be impeding the

free movement of the caliper.

WARNING: Not all wheels and valve stems are

compatible with Bendix Air Disc Brakes. Use only

wheels and valve stems approved by the vehicle

manufacturer to avoid risk of valve stem shear and

other compatibility issues. After re-installing a wheel

according to the vehicle manufacturer’s recommendations,

please ensure that there is sufficient clearance between

Check the clearance at

the tire inflation valve stem, the caliper and the wheel rim,

both tappets simultaneously:

to avoid damage.

0.024 in. to 0.043 in.

(0.6 mm. to 1.1 mm.)

Figure 16 - Running Clearance Check

CAUTION: If the clearance is too wide, there is a

danger of brake failure. If the clearance is too small,

or if there is no gap at all, there is a danger of the brake

overheating. These conditions must be corrected

before returning the vehicle to service.

For further investigation, where there is some gap, go to

Section 4.2 and check the adjuster mechanism. Where

there is no movement at all (and so no gap to measure),

go to Section 4.5 “Guide Pin Inspection.”

4.2 adjuster mechanism Inspection

CAUTION: Follow all safe maintenance practices.

Aside from the normal maintenance schedule, the

adjuster mechanism inspection that follows is also

carried out when the Caliper Movement Test (4.1) finds

that the running clearance is too small or too large.

4.2.1

With the spring brake released (or caged), remove

the adjuster cap (37) using the tab, taking care not

Figure 20 - Backing-off (increasing) the Running

to move the shear adapter (61). Note: One of two

Clearance

styles of adjuster cap (stamped metal or plastic

If the shear adapter fails, you may attempt a second time

adjuster cap) may be used.

with a new (unused) shear adapter.

Note: Always double-check that the spring brake is released

(where applicable) if a shear adapter fails; if this step was

missed, the shear adapter will break off, and it may appear

that the caliper is seized.

In cases where a second failure of the shear adapter

confirms that the adjustment mechanism is seized, the

caliper must be replaced.

Adjuster Cap

Location

Figure 17 - adjuster cap location

Figure 21 - Applying moderate applications of the

Cap

brakes: the

wrench moves clockwise as the running

clearance is diminished

4.2.3

Where the adjuster mechanism is able to be backed-

23 Adjuster

off normally, position a box-end wrench on the shear

61 Adapter

adapter so that it can turn clockwise freely without

coming into contact with parts of the vehicle (See

Cap

Tab

Figure 21). Make five to ten moderate applications

of the brakes [at about 30 psi (2 Bar)], and observe

Figure 18 - Exploded view

Figure 19 - CAP INSTALLED:

of adjuster and adapter

tab location

that the box-end wrench or socket should turn

clockwise in small increments.

For illustration purposes, the exploded view (Figure 18)

shows the adjuster (23) and shear adapter (61) separated.

NOTE: As the number of applications increases,

the turning movement will decrease (as the brake

When using the adjuster mechanism, always have the

shear adapter installed on the adjuster.

reaches its normal calibration point).

4.2.2

Using a 10 mm. six-point box wrench, turn the Shear

If the box-end wrench does not: (a) turn at all; (b) turns only

Adapter (61) counter-clockwise and listen for

with the first application; or (c) turns forward and backward

the sound of 3 clicks as the mechanism backs-off

with every application, the automatic adjuster has failed and

(increases) the running clearance. Note: Do not

the caliper/carrier assembly must be replaced.

use an open-ended wrench as this may damage

After completing these wheel-off tests, Bendix recommends

the adapter. See Figure 20.

installing a new adjuster cap (lightly greased using white,

CAUTION: Never turn the adjuster (23) without the

lithium-based grease) when returning the brake to service.

shear adapter (61) installed. The shear adapter is a

Ensure that the tab is in the position shown in Figure 19.

safety feature and is designed to prevent excessive

torque from being applied to the adjuster. The shear

adapter will fail (by breaking) if too much torque is

applied.

4.3- 4.4 Brake Pads and Rotors

4.3 Inspect the Brake Pads

CAUTION: Follow all safe maintenance practices.

Regular inspection of the brake pads (even for vehicles

that use an electronic wear indicator) is an important part

If electronic wear sensors are present, see Section 5.2.

of vehicle maintenance.

If dust covers are present, see Section 5.1.

4.3.1

See Figure 22. If the thickness of the friction

See Figure 23. While pressing down against the pad

material — dimension “C” — is less than 0.080 in.

retaining bar (11), remove and retain the clip (26),

(2 mm.), the pads must be replaced.

washer (45) and pin (44). Remove the pad retainer bar (11).

Bendix^® ADB22X^™, ADB22X-V^™ air disc brakes use 0.35 in.

Bendix recommends that these items should be replaced

(9 mm.) backing plates, so dimension “D” (the combined

with new (See available kits and parts, Section 5.0).

pad and backing plate thickness) must be a minimum of

0.43 in. (11 mm.).

Follow the steps in Section 4.2 for backing-off the adjuster

mechanism. Slide the caliper inboard then outboard to

4.3.2

Check for uneven end-to-end pad wear. If the

difference in wear is greater than 0.080 in. (2 mm.),

permit easy removal of the brake pads.

replace the brake pads and also inspect the guide

pins (See Section 4.5).

Brake Rotor

4.3.3

Compare the thickness of the inboard and outboard

Outboard

pads of each set. If the difference between the

Brake Pad

inboard and outboard pad thickness is greater than

0.138 in. (3.5 mm.), replace the brake pads and

inspect the guide pins (See Section 4.5).

If the results of the pad inspections are within the acceptable

range, inspect the pad surface. (See Figure 24).

Inboard

Brake Pad

Where a

small amount

of brake

Minor Damage -

material

Is Acceptable

chipped from

the edge

Thickness of a new pad (1.181 in.) (30 mm.).

Backing plate thickness (0.360 in.) (9 mm.)

Minimum thickness of friction material (0.080 in.)

(2 mm.)

Minimum thickness of a worn pad (0.433 in.)

(11 mm.); replace pads.

Major Damage -

Thickness of a new rotor (1.77 in.) (45 mm.).

Is Not Acceptable

Minimum rotor thickness (1.46 in.) (37 mm.)

Section

damaged or

Figure 22 - PAD AND ROTOR DIMENSIONS

missing

See Figure 22 for initial brake pad and rotor dimensions,

as well as minimum acceptable dimensions.

Figure 24 - brake PAD surface inspection

Minor damage at the edges is permitted, but replace the

pads if major damage on the surface of the pad is found.

When replacing brake pads, Bendix strongly recommends

that all the brake pads on an axle be replaced at one time.

See Section 5.1 for the pad replacement procedure. Also

see the vehicle manufacturer’s recommendations found in

the operator’s manual.

11 Pad Retainer Bar

45 Washer

26 Spring Clip

Figure 23 - Retainer bar removal

Bendix air disc brakes are precision-engineered braking

4.4.1

Measure the thickness of the brake rotor at the

mechanisms. The “friction couple” braking characteristics

thinnest point (Dimension “E” in Figure 22). Avoid

have been carefully optimized — and the rotor design and

measuring near the edge of the rotor as minor

materials have been matched with special formulation

burrs may result in inaccurate measurement. For

brake pads for optimal performance. In all cases, use

Bendix^® brand rotors, replace the rotor when

brake pads with the type of backing plate and lining material

the minimum thickness of 1.46 in. (37 mm.) is

originally supplied by the vehicle manufacturer.

reached. For other brands of rotors, refer to the

rotor manufacturer’s guidelines.

CAUTION: When replacing brake pads and rotors,

use only Bendix^® brand replacement pads and rotors

4.4.2

Inspect the rotor surface. See Figure 25. The type

and/or those approved by the OEM. Non-approved

of rotor, and also the size, depth and direction of

replacement disc pads or rotors can cause excess

the imperfections, must all be considered.

wear to brake components, and can increase the risk

Note: If surface wear conditions F through J are

of rotors cracking, etc.

in the permitted range, the rotor is still usable until

it reaches the minimum acceptable thickness for the

4.4 Inspect the Rotor

rotor manufacturer’s guidelines.

CAUTION: Follow all safe maintenance practices.

4.4.3 Machining (Grinding or Turning) Rotors

Identify if the rotor is a Bendix^®Splined Disc^®, or Bendix^®

Bendix^® brand rotors are normally service-free. In the case

brand conventional rotor (See Section 1.03). Rotors should

of severe grooving of the entire friction surface, however,

be inspected regularly (See Section 2.0 for recommended

conventional rotors may be turned when changing

inspection schedule) and at each pad change.

pads, to increase the load-bearing surface.

•

For standard Bendix^® brand rotors,

No action is needed

for small cracks

cracks running in a radial direction —

like spokes of a wheel (see Area H)

spread over the

Area

surface (e.g. Area F)

Area

— less than 0.06 in. (1.5 mm) deep or

wide are acceptable if they do not reach

either edge (see G). Cracks are only

acceptable if the length of the crack is

less than 75% of dimension “f” (the width

Rotor

of the rotor contact area).

Friction

•

For Bendix^® Splined Disc rotors,

Surface

radial cracks are only acceptable if they

Width “f”

are less than 0.04 in. (1.0 mm) deep

or wide and if they do not reach either

edge (see G). Crack lengths must be

less than 75% of dimension “f” (the

Area G

Area J

width of the rotor contact area).

Cracks reaching

either edge of the

rotor

are not

In addition, follow the

acceptable

recommendations of

Circumferential

for either

the vehicle and rotor

grooves, as in Area

type of

manufacturer.

J, are acceptable

rotor

if less than 0.06 in.

Note: Axles should

(1.5 mm) deep.

have either all Bendix

Splined Disc (or all

conventional) rotors.

Figure 25 - examples of acceptable and non-acceptable rotor conditions

Machining of Bendix^® Splined Disc^® rotors is

not permitted.

Guide Pin

Brass Bushing

Caliper

Inner Boot

CAUTION: Always maintain air disc brake pads and rotors

within specifications. Excessive pad or rotor wear will

degrade braking performance.

Cap

long

bearing side

Periodic inspection of the Bendix Splined Disc attachment

hardware is recommended to ensure optimum braking

performance. Bendix recommends verifying the torque on

the spring element fasteners whenever a brake inspection

is performed.

WARNING! After machining/turning,

the minimum rotor thickness for Bendix^®

brand rotors must be at least 1.535 - 1.575 in.

(39 - 40 mm.) - for other brands, consult the

manufacturer’s guidelines. Also, Check the

vehicle manufacturer’s recommendations.

short

Failure to comply may result in brake failure

bearing side

and in serious injury or death. MACHINING of

Bendix splined disc rotors is not permitted.

4.4.4 Rotor Replacement

An axle is permitted to have only all Bendix Splined

Disc, or all conventional, rotors.

When replacing rotors, be sure to adhere to the vehicle

6 Guide Sleeve

manufacturer’s recommendations, including bolt tightening

Caliper

torques. It is recommended to install only Bendix^® brand

Movement

Outboard

Inboard

rotors, and also that the pads should be replaced (as an

axle set) at the same time.

Caliper Bolt

Cap

Non-Bendix^® brand rotors. If a non-Bendix^® brand rotor is

4 Guide Pin

9 Inner Boot

used, confirm that it complies to the vehicle manufacturer’s

recommendations.

Figure 26 - guide pins

CAUTION: The use of non-approved brake rotors may

12 Pad Assembly

reduce levels of safety and invalidate the warranty.

Carrier

See Section 5.7 for re-installation procedures.

4.5 Guide Pin Bearing Inspection

CAUTION: Follow all safe maintenance practices.

This guide pin inspection should be carried out if the

technician cannot move the caliper during a Caliper

Magnetic

Movement Test (Sections 2.2 and/or 4.1).

Dial-Gauge

Measures

Measure the range of travel along the guide pin

Range Here

Caliper

bearings:

Figure 27 - Magnetic dial-gauge in use

4.5.1

Remove the Pads (See Section 4.3). Using hand

pressure only (no tools), the caliper (1) should slide

Measure the “play” (range of movement) in the guide

freely along the whole length of the guide pins. This

pin bearings:

movement should be at least 0.95 inch (25 mm)

4.5.2

See Figures 26 and 27. With the wheel removed,

when the pads are not present. If the movement

remove the pad retainer bar (11). Temporarily

is less than this amount, replace the caliper/carrier

replace the pads with two new pads (12). Attach

assembly.

a magnetic dial-gauge holder to the carrier (2) on

the short bearing side of the caliper (1). Use the

measuring point on the caliper (1) - see the callout

in Figure 27. Press the caliper in the direction of

4.6 Tappet and Boot Assembly

the carrier (2) and set the dial-gauge to zero.

Inspection

4.5.3

Place a suitable tool (e.g. a large flat-blade

4.6.1

In order to inspect the tappet and boot assembly,

screwdriver) between carrier (2) and caliper (1) and

remove the pads (12) (See Sections 4.3 or 5.2) and

use light hand force to move the caliper away from

advance the shear adapter (61) clockwise.

the carrier, until the movement stops. Read the

CAUTION: Never extend the tappet more than

maximum value on the dial-gauge. See Figure 27.

1.75 in. (44.5 mm). See Figure 29. Over-extending the

If the value is greater than 0.039 in. (1.0 mm), replace

tappet will result in the tappet losing engagement with

the guide pin bushings (See Section 5.6) OR replace the

the synchronizing mechanism. Since the mechanism

caliper/carrier assembly (See Section 5.3).

can only be set at the manufacturing plant, the caliper/

carrier assembly must be replaced if this happens.

Inspect the guide pin inner boots:

4.6.2

Inspect the tappet and boot assemblies

4.5.4

See Figures 28 and 29. With the pads removed,

(13) for evidence of damage, cuts,

slide the carrier by hand to the inboard position (See

cracks, tears and evidence of

Figure 28). By looking through the opening where

corrosion, etc. Damaged boots lead to the

the pads are installed — and also from below —

penetration of dirt and moisture, and can lead to

inspect the inner boot (9) for each of the guide pins.

corrosion and impair the operation of the brake.

Inspect for damage, cuts and cracks.

Replace as necessary (See Section 5.5).

Replace damaged boots immediately to prevent

dirt and/or moisture affecting the movement of the

guide pins (See Section 5.4). Damaged or corroded

guide pins will impair the operation of the brake.

In addition, during installation, the boots are

compressed to minimize the amount of air trapped

within them. Observe as you move the carrier back

towards the outboard position; the boots should only

expand outwards a small amount due to trapped

air. The boots should normally (due to their ribbed

construction) contract back into place as the caliper

moves on the guide pins. The boots are not air-

tight and so some trapped air is normal; excess air

trapped will dissipate.

Extend LESS THAN

1.75 in. (44.5 mm.)

Figure 29 - permitted tappet extension

Where the tappets and boots pass the inspection, retract

the tappets using the shear adapter.

When installed, the boots are compressed to minimize the

amount of air trapped within them. Observe as you move

the tappet back using the shear adapter; the boots should

only expand outwards a small amount due to trapped air.

Inspect

The boots should normally (due to their ribbed construction)

Boot

contract back into place as the tappets move. Note: If the

bellows have excess air trapped, then with the tappets

Figure 28 - Guide pin boot inspection (this image does

not show the carrier)

retracted, remove and re-install the actuator to vent the

4.5.5

Inspect the original pads (See Section 4.3) and they

excess trapped air (See Section 5.4).

may be reused if they are in good condition with

Follow the reinstallation steps for the brake pads (See

sufficient pad thickness.

Section 5.2).

Section five: Maintenance Kits and procedures

Section Five

Section

Page

Section

Page

5.0

Maintenance Kits

16-18

5.4

Spring/Service Brake

5.1

Air Disc Brake Shield Kit

5.5

Tappet & Boot, and Tappet Inner Seal

25-28

5.2

Pad Replacement

5.6

Guide Pin and Boot Assemblies . .

29-34

5.3

Caliper/Carrier/Actuator Assembly

22-23

5.7

Bendix^® Splined Disc^® Hub Rotor

35-37

(Wheel turns toward

fixed pin side of

18/1 Spring Brake

Type A

Type B

Actuator

ADB)

(Fixed pin)

11 Pad Retainer

Pad Retainer Pin

18/2

26 Spring Clip

Service

Actuator

12/2 Pad Holder Spring

(Pad Assembly

consists of

12/1 plus 12/2)

Cap

12/1 Pad

Caliper

Washer

Bolt

Wheel Rotation

Guide

(typically right hand)

(typically left hand)

Brass

Bushing

Cap

Shield

39 Caliper Bolt

Kit

Inner Seal

161

(Drive or

Tappet Bushing

4 Guide Pin

*37 Adjuster

Actuator

Steer)

Hardware

Caps (2 styles

13 Tappet

37*

6 Guide Sleeve

supplied in kits)

and Boot

Shear

Assembly

Adapter

Carrier

Mounting

Hardware

Caliper

U-shaped Rotor

(or Caliper Kit)

Inner Boot

Ring

Bendix^®ADB22X^™

Anchor Plate

Bendix^®

(Rotor Shield for Trailers)

ADB

U-shaped

Rotor

Fasteners

SD-

Drive Hub

SD-2

Bendix^®

ADB22X-V^™

Splined Disc^® Rotor

Anchor Plate

SD-3

Hardware

Carrier

SD-1, -2, -3

Mounting

Hardware

See Section 5.2 for

Splined Disc^® Rotor

exploded view of electronic

(SD)

wear indicator.

Steer Hub

Figure 30 - exploded view - Bendix^® ADB22X^™ and ADB22X-V^™ Air Disc Brakes

5.0 Maintenance Kits for Bendix^® ADB22X^™ and 22X-v^™Air disc Brakes

Below is a list of some of the available kits. See Figure 30 for an exploded view showing the components listed.

Piece

Kit

Components Included in Kit

Number

Pad Kit (axle set)

K070796

(11, 12/1, 12/2, 26, 37, 44, 45, 61)

Splint Kit (box of 25)

803151

(26)

Shear Adapter (box of 10)

802455

(61)

Tappet/Boot Kit (wheel end kit)

K092079

(13, 22, 161)

Adjuster Cover (box of 10)

802643

(37)

Guide Pin, Seal and Boot Kit

803114

(4, 5, 6, 7, 9, 10, 37, 39, 40, 58, 61, 68)

(wheel end kit)

Guide Pin Boot Kit

K023768

(9, 10, 37, 39, 40, 58, 61, 68)

II14525

White (5 grams)

Guide Pin Grease

K021964

White (500 grams)

K028039

Bendix^® Type 14 Universal (9, 18/2)

K028226

Bendix^® Type 16 Universal (9, 18/2)

K028022

Bendix^® Type 18 Universal (9, 18/2)

Service Actuators

K028225

Bendix^® Type 20 Universal (9, 18/2)

K028238

Bendix^® Type 22 Universal (9, 18/2)

K028252

Bendix^® Type 24 Universal (9, 18/2)

K027557

Bendix^® Type 18/16 Piston Style Truck/Trailer Universal (1, 18/1)

NG-3 Piston Style

K025670

Bendix^® Type 18/24 Piston Style Truck/Trailer Universal (1, 18/1)

Spring Brake Chambers

K025669

Bendix^® Type 20/24 Piston Style Truck/Trailer Universal (1, 18/1)

K042457

Bendix^® Type 16/24 Double Diaphragm Style (35)

K043329

Bendix^® Type 18/24 Double Diaphragm Style (35)

Double-Diaphragm Style

K041960

Bendix^® Type 20/24 Double Diaphragm Style (35)

Spring Brake Chambers

K043148

Bendix^® Type 22/24 Double Diaphragm Style (35)

K043270

Bendix^® Type 24/24 Double Diaphragm Style (35)

K081142

12 Degree Steer and Drive Axial “A” (2A, 1)

K081143

12 Degree Steer and Drive Axial “B” (2A, 1)

Caliper-Carrier Assembly

802984

Zero Degree Trailer Axial “A” (2A, 1) [Zero degree dual-beam carrier.]

(Includes 803114)

802985

Zero Degree Trailer Axial “B” (2A, 1)

K081256

12 Degree Steer and Drive Vertical “A” (2B, 1)

K081257

12 Degree Steer and Drive Vertical “B” (2B, 1)

K081258

12 Degree Steer and Drive Axle “A” (1)

Caliper Kit

K081259

12 Degree Steer and Drive Axle “B” (1)

(rationalized)

K019180

Zero Degree Trailer Axle “A” (1)

Includes 803114

K019181

Zero Degree Trailer Axle “B” (1)

K051853

Steer and Drive Axle, Axial (2A, 9, 10, 20, 39, 40, 58, 61, 68)

Carrier Kit

K043288

Trailer Axle, Axial (2A, 9, 10, 20, 39, 40, 58, 61, 68)

K056559

Steer and Drive Axle, Vertical (2B, 9, 10, 20, 39, 40, 58, 61, 68)

K020505

Splined Disc^® Brake - Aluminum - FF Steer, LMS Bearing Package (Steer Hub)

803134

Splined Disc^® Brake - Aluminum - FL Steer, LMS Bearing Package (Steer Hub)

802847

Splined Disc^® Brake - Aluminum - R Drive, LMS Bearing Package (Drive Hub)

K020514

Splined Disc^® Brake - Aluminum - FF Steer, Standard Bearing Package* (Steer Hub)

803138

Splined Disc^® Brake - Aluminum - FL Steer, Standard Bearing Package* (Steer Hub)

802859

Splined Disc^® Brake - Aluminum - R Drive, Standard Bearing Package* (Drive Hub)

Hubs

K045298

Splined Disc^® - Aluminum - "TN" Trailer, Standard Bearing Package* (Drive Hub)

K045297

Splined Disc^® - Aluminum - "TP" Trailer, Standard Bearing Package* (Drive Hub)

See hub

U-shaped - Iron/Aluminum, LMS/Standard Bearing Packages

supplier

for these

standard

Flat - Iron/Aluminum, LMS/Standard Bearing Packages

hub

products

Bendix® Splined Disc® Rotor Attaching Kit

K037767

All Splined Disc^® Rotor Applications (SD-1, SD-2, SD-3)

Table 2 - Maintenance Kits

(Continues over)

Piece

Kit

Components Included in Kit

Number

802081

Severe Duty 138mm U-shaped Rotor and Fasteners

K038573

Heavy Duty 138mm U-shaped Rotor and Fasteners

802082

Severe Duty 150mm U-shaped Rotor and Fasteners

Rotors

K038574

Heavy Duty 150mm U-shaped Rotor and Fasteners

802083

Severe-Duty Splined Disc Kit (SD-1, SD-2, SD-3, SD)

802569

Heavy-Duty Splined Disc Kit (SD-1, SD-2, SD-3, SD)

803129

(Dana) Trailer Axle Pad & Rotor Shield Kit

803130

Axial Drive Axle Pad & Rotor Shield Kit

Shields

802948

Pad Shield Kit

K032135

Vertical Drive Axle Pad & Rotor Shield Kit

k022168

Vertical Drive Axle Rotor Shield

Table 2 - Maintenance Kits (continued)

See the Bendix Quick Reference Catalog (BW1114) for maintenance kits for other Bendix^® brand Air Disc Brakes.

5.0.1 General information about

•

When replacing bearings — or for any other

maintenance procedure where the technician needs

Bendix^® air DISC brake maintenance

to remove the caliper/carrier assembly from the vehicle

When working on Bendix^® Air Disc brakes, please note

to perform the maintenance — replacement caliper/

the following:

carrier bolts will be required. Please note that due

•

Read and follow the Safe Maintenance Practices on

to the high torque required, the original bolts cannot

page two.

be reused. The bolts are available from the vehicle

manufacturer.

•

Depending on the particular axle, the technician may

need to remove the caliper/carrier to allow sufficient

•

WARNING: Not all wheels and valve stems are

access to perform the work.

compatible with Bendix Air Disc Brakes. Use only

wheels and valve stems approved by the vehicle

•

CAUTION: When using a hoist to support the air

manufacturer to avoid risk of valve stem shear and

disc brake, do not attempt to use the pad retainer

other compatibility issues.

bar as a bracing point as it is not designed to

support the weight of the brake. Instead use a

5.0.2 Service DVD

brace (or chain) wrapped around the entire brake

Order part number BW7356 for a DVD showing the full

to attach the hoist.

set of maintenance procedures included in this Service

Data sheet.

Remove Caliper/

Remove

Carrier from

Actuator from

See

Brake Pads?

Kit

Vehicle?

Caliper?

Section

Section 5.2

Section 5.3

Section 5.4

Dust Shields

Section 5.1

Not Typically

Pad Kit (axle set)

Section 5.2

Yes

Caliper Kit (rationalized)

Section 5.3

Yes

Carrier Kit

Section 5.3

Yes

Service Actuator

Section 5.4

Not Typically

Yes

Spring Brake Actuator

Section 5.4

Not Typically

Yes

Tappet/Boot Kit (wheel end kit)

Section 5.6

Yes

Typically

Guide Pin, Seal and Boot Kit (wheel end kit)

Section 5.7

Yes

Typically

Hubs

Section 5.8

Yes

Splined Disc^® Rotor Attaching Kit

Section 5.9

Yes

Rotor

Section 5.10

Yes

Table 3 - Other required sections for Maintenance kits

5.1 Air disc brake shield kit

5.1.2

Remove and discard the spring clip and washer

from the pad retainer pin. Remove and retain the

5.1.1

CAUTION: Follow all safe maintenance

retainer bar and retainer pin. Position the pad shield

practices, including those listed on page two of

as shown and re-insert the retainer bar. Install

this document. Park the vehicle (by other means

the retainer pin. Use the included spring clip and

than the foundation brakes) on level ground and

washer to secure the retainer pin. Check that the

chock the wheels.

pad shield is held securely in place by the retainer

Note: Most torque plates manufactured after January 1,

bar. See Figure 31 or 32.

2007 have the required torque plate tabs to permit these

Spring

shields to be mounted.

Clip

This shield kit includes a brake pad shield, a rotor shield

Washer

and the required attaching hardware for use in Bendix^®

ADB22X^™ and ADB22X-V^™Air Disc Brake applications

Pad Shield

where external contamination and excessive road debris is

a concern. Brake pad and rotor shields can greatly reduce

damage and/or premature wear of pads and rotors under

these conditions.

During installation, verify that once the shield(s) are

installed they will not come into contact with any vehicle

components, suspension, housings, etc. through the full

range of motion of the wheel. Keep in mind the particular

use of the vehicle, the orientation of the brake on the axle

Rotor Shield

and torque plate, the proximity of other axles, and/or the

wheel/tire being used.

Washer

Torque

Plate

Spring

Fastener

Clip

(with Washer)

Fastener

Rotor

Lock

Shield

Washer

Pad Shield

Figure 32 - Trailer Axle Exploded view with inset

showing rotor shield installation

5.1.3

Drive or Steer Axle Rotor Shields (See Figure

31). Position the rotor shield between the torque

plate and the rotor. The supplied cap screws

pass through the mounting tabs in the torque plate

and install into the shield. Torque cap screws to

44 Ft. Lbs. (528 in. lbs.).

5.1.4

Trailer Axle Rotor Shields (See Figure 32).

Position the rotor shield with the torque plate

between the shield and the rotor. With one

Rotor Shield

(supplied) lock washer in place on each cap screw,

pass the screws through the shield before mounting

Fastener

Torque

Plate

onto the threaded torque plate holes. Torque the

cap screws to 24 ft. lbs. (288 in. lbs.).

Fastener

Note: The installation of air disc brake shields does not

Rotor Shield

eliminate the need for periodic maintenance and inspection

of the air disc brake and entire wheel end for damage and/

or wear. In addition, the truck and trailer manufacturer’s

Figure 31 - Drive or Steer Axle Exploded view with

inset showing rotor shield installation

specific criteria for the brake shield requirements on air

disc brakes should be consulted before either installing or

removing air disc brake shields from a wheel end(s).

5.2 Pad Replacement

and retain the mounting hardware for the cable

5.2.1

CAUTION: Follow all safe maintenance

protection plate. The cable protection plate can

practices, including those listed on page two of

then be set aside while servicing the pads. Note the

this document. Park the vehicle (by other means

position of the sensors in the brake pad channels,

than the foundation brakes) on level ground and

and carefully remove them. In most cases you do

chock the wheels.

not need to release the cable connector in order to

The Bendix DVD (BW7356) shows this procedure.

move the sensors away from the pad installation

work area. Inspect the wear sensors - replace if

Important: If the vehicle is equipped with spring brakes,

damaged or abraded.

cage the spring brakes on all axles to be worked on.

Consult the vehicle manufacturer’s instructions as

5.2.4

See Figure 34. Remove and discard the pin

necessary. For Bendix piston-style, see Section 5.4.

retention clip (26) and washer (5).

ELECTRONIC WEAR

SENSOR

104

(if installed)

Cable Protection

101

Plate

Sensor

105

101

Cable Guide

Sensor

(2 alternate

designs used)

11 Pad Retainer Bar

45 Washer

103

Cable to Electrical

26 Spring Clip

Supply

Figure 34 - Pad retainer bar removal

5.2.5

While pressing against the pad retainer bar, remove

the pin (11). Discard the pad retainer bar.

5.2.6

With the spring brake released (or caged), remove

the adjuster cap (37) using the tab, taking care not

to move the shear adapter (61). Note: Two sizes

of adjuster cap are supplied in kits; use the same

size as before in step 5.2.20.

5.2.7

Inspect the shear adapter (61). If significant

corrosion and/or damage is present, remove the

adjuster adapter using needle-nose pliers and

replace with the adapter supplied in the kit and

clean as necessary.

Cap

23 Adjuster

61 Adapter

Cap

Tab

Figure 35 - Exploded view

Figure 36 - CAP INSTALLED:

of adjuster and adapter

tab location

Figure 33 - Pad replacement

For illustration purposes, the exploded view (Figure 35)

5.2.2

Raise the complete axle to be worked on until the

shows the adjuster (23) and shear adapter (61) separated.

tires clear the ground. See the vehicle maintenance

When using the adjuster mechanism, always have the

manual instructions for removing the wheels.

shear adapter installed on the adjuster.

5.2.3

If the air disc brake is equipped with an electronic

wear sensor indicator (see top of Figure 33), remove

CAUTION: Never turn the adjuster (23) without the

Use these two inspections:

shear adapter (61) installed. The shear adapter is a

A. Check for uneven end-to-end pad wear. If

safety feature and is designed to prevent too much

the difference in wear is greater than 0.080 in.

torque being applied. The shear adapter will fail (by

(2 mm.), replace the brake pads and also inspect

breaking) if too much torque is used.

the guide pins (See Section 4.5).

Note: For wheel-ends with spring brakes, if a shear adapter

B. Compare the thickness of the inboard and

fails, always double-check to verify that the spring brake

outboard pads of each set. If the difference

has been released (or caged). If the spring brake is applied,

between the inboard and outboard pad thickness

release or cage the brake (assure that the air system

is greater than 0.138 in. (3.5 mm.), replace the

pressure is at least 90 PSI) and start the procedure again.

brake pads and inspect the guide pins (See

If the shear adapter fails, you may attempt a second time

Section 4.5).

with a new (unused) shear adapter. In cases where a

5.2.12 Inspect the Brake Rotor (See Section 4.4).

second failure of the shear adapter confirms that the

5.2.13 Inspect the guide pins (See Section 4.5).

adjustment mechanism is seized, the caliper must be

replaced.

Important: To maintain optimal braking, Bendix

5.2.8

Use a 10 mm., six-point box wrench (See Figure 37)

strongly recommends that whenever brake pads

are replaced, the complete axle set be replaced

to turn the adjuster counterclockwise until sufficient

space exists to remove the brake pads. A clicking

together. Use only pads which are permitted by the

vehicle manufacturer, axle manufacturer, and/or disc

noise occurs each time the adjuster turns.

brake manufacturer. Failure to comply with this may

Caution! Avoid overloading or damaging the adjuster

invalidate the vehicle manufacturer’s warranty.

shaft. Do not use an open-ended wrench since it may

Before installing the brake pads, use the adjuster to

damage the adjuster shaft.

fully retract the tappets to provide adequate clearance.

5.2.14 Clean the surfaces that will come in contact with

the brake pad.

Caution: When installing pads and retaining springs,

where appropriate, use heavy duty gloves and always

keep fingers away from potential pinch hazard areas.

Figure 37 - backing off the Adjuster for pad removal

Figure 39 - Pad Retaining Spring Installation

5.2.15 Install the pad retaining springs(2) onto the brake

pads(12) by inserting one end of the spring onto

the lug at the top of the brake pad (See Figure 39).

Carefully apply enough force to permit the second

Inboard Pad

lug to fully engage, taking care to keep fingers etc.

away from the spring as it seats.

Figure 38 - Pad removal

5.2.16 Pull the caliper fully outward and install the outboard

5.2.9

See Figure 38. Move the caliper fully inward and

pad. Move the caliper fully inward and install the

remove the inboard pad, then move the caliper fully

inboard pad.

outward and remove the outboard pad.

5.2.17 To reinstall wear indicators (if used): Insert the

5.2.10 Repeat the pad removal procedure for the other

wear sensors into position in the new brake

end of the axle.

pads. Route the sensor cable through the cable

protection plate channel and secure the plate with

5.2.11 To confirm that the guide pins are sliding freely,

the mounting hardware retained at disassembly.

examine the pads just removed for uneven wear.

(See Section 5.2.)

5.3 Caliper/carrier/actuator

assembly

CAUTION: Follow all safe maintenance practices,

including those listed on page two of this document.

Park the vehicle (by other means than the foundation

brakes) on level ground and chock the wheels.

CAUTION: When using a hoist to support the air disc

brake, do not attempt to use the pad retainer bar as a

Figure 40 - Running Clearance Adjustment

bracing point. It is not designed to support the weight

5.2.18

Using a 10 mm., six-point box wrench, turn the

of the brake. Use instead a brace (or chain) wrapped

Shear Adapter (61) clockwise until the pads contact

around the entire brake to attach the hoist.

the rotor. Note: Do not use an open-ended wrench

5.3.1

In all cases check that the current hose routing

as this may damage the adapter. (See Figure 40).

arrangement does not restrict the full travel of the

5.2.19

Using the same tool, turn the Shear Adapter (61)

caliper before beginning work on the assembly.

counter-clockwise and listen for the sound of 3

5.3.2

Remove the brake pads (See Section 5.2).

clicks as the mechanism backs-off (increases) the

running clearance. (See Figure 37).

5.3.3

(See Section 5.4). If the actuator used is a spring

brake, following the manufacturer’s guidelines, cage

5.2.20

Select the correct replacement adjuster cap from

the spring. With all air pressure drained from the

those supplied with the kit. Lightly grease adjuster

system, disconnect the air hoses from the brake

cap with Renolit HLT2 white grease (part number

chamber.

14525) and install the cap.

Vertical Mounting Bolt Style

5.2.21

Push the new pad retainer bar (11) into the groove

of the caliper. Press down on the pad retainer bar,

Caliper/Carrier Assembly (Showing

and insert the pad retainer pin (44), with the pin

Spring Brake Actuator )

pointing downwards, where possible. Install the

supplied washer (45) and then the spring clip (26).

(See Figure 34).

5.2.22

Apply and release the brakes. The hub should

Alignment

Bushing

turn easily by hand after applying and releasing the

Anchor Plate/

brake.

Torque Plate

5.2.23

Re-check the running clearance. Readjust if

necessary.

5.2.24

Reinstall the wheel, following the vehicle manual

Alignment

Bushing

instructions.

Mounting Bolts

(6 total - washers

WARNING!

not required)

The brake pads and rotor must be maintained within

the recommended wear limits. Failure to monitor wear

Figure 41 - vertical mount caliper/carrier

and replace the brake pads and rotor when required

5.3.4

See Figure 41. Supporting the air disc brake by

may result in diminished brake performance.

necessary means, remove the six (6) mounting

bolts/washers and discard. Note: Bendix strongly

recommends that during re-assembly these bolts

are replaced - see your vehicle manufacturer for

replacement hardware. Lift the caliper up off the

anchor plate.

The vertical bolt assembly includes an alignment bushing.

This bushing must be saved for re-use during re-

assembly of the brake. The bushing mounts in the torque

plate and maintains the correct alignment of the brake

assembly relative to the rotor.

5.3.5

If the brake assembly does not separate from the

anchor plate it may be helpful to install an M16X2.0

Caliper/Carrier

screw longer than 120 mm at the bushing locations

Assembly

(Actuator not

and tap the end of the bolt with a hammer to free

shown)

the brake assembly. Remove the assembly.

Axial Mounting Bolt Style

Mounting Bolts

5.3.6

Disconnect the air hose(s) to the brake chamber.

and Washers

(6 sets total)

See Figure 42. Supporting the air disc brake by

necessary means, remove the six bolts attaching

the brake to the anchor plate and remove the

caliper/carrier assembly from the vehicle.

Note: Bendix strongly recommends that during re-assembly

these bolts and washers are replaced. See your vehicle

Anchor Plate/

Torque Plate

manufacturer for replacement hardware. Remove the

assembly.

Re-installation (Both Styles)

5.3.7

Supporting the air disc brake by necessary means,

Figure 42 - Axial mount caliper/carrier

attach the brake to the anchor plate using six

5.3.8

Re-install the air hoses (See Section 5.4.8-9) and

(new) bolts. Torque to vehicle manufacturer’s

check for leaks.

specifications. If torque values and bolts are not

specified by the vehicle manufacturer, then select

5.3.9

Inspect and re-install the pads (See Section 5.2).

a replacement bolt as shown in Table 4.

Air Disc Brake Attachment Hardware

Torque Plate Manufacturer

Fastener

Torque

Bendix Axial

Fastener: M20 x 2.5 x 60 mm Class 10.9

Carrier Torque Plate

Washer: Requires a THROUGH

Use the manufacturer’s recommendations.

HARDENED 3 mm (minimum thickness) for

each bolt.¹If the vehicle is using a Bendix

If unavailable, use phosphate

and oil finish fastener.

manufactured Axial Anchor Plate, with a

thickness of 1.14 in. (29 mm) where these

Pre-Torque: 20-60 ft-lbf [27-81 N·m]

bolts are assembled, then a bolt with an

overall length of 2.36 in. (60 mm) will meet

Final Torque: 350-400 ft-lbf [475-542 N·m]

these requirements

Bendix Vertical

Carrier Torque Plate

Use the manufacturer’s recommendations.

Fastener: M16 x 2.0 x 110 mm, Class 10.9

If unavailable, use plain and oil finish fastener.

Washer: None required.

Torque: 200-220 ft-lbf [271-298 N·m]

Fastener: M20 x 2.5 x L Class 10.9

Use the manufacturer’s recommendations.

Length determination:

If unavailable, use phosphate

L = Torque Plate (TP) thickness + Carrier

and oil finish fastener:

engagement + Washer thickness

Trailer Torque Plate

L_min = TP thickness + 24 mm + 3 mm

Pre-Torque: 20-60 ft-lbf [27-81 N·m]

L_max = TP thickness + 29 mm + 3 mm

Final Torque: 350-400 ft-lbf [475-542 N·m]

Washer: Requires THROUGH HARDENED

3 mm (minimum thickness) for each bolt.¹

Footnote 1 CAUTION: The washer outside diameter must be less than 1.5 in (37.5 mm).

Recommended washers conform to DIN125-21-300HV, ISO7089-20-300HV, or ISO7090-20-300HV.

Table 4 - Torque plate fasteners and torque recommendations (see Manufacturer’S recommendations)

5.4

Spring or Service Brake

5.4.1

CAUTION: Follow all safe maintenance

practices, including those listed on page two of

this document. Park the vehicle (by other means

than the foundation brakes) on level ground and

chock the wheels.

5.4.2

Use the spring brake manufacturer’s recom-

mended safety practices in all cases.

Some spring brake and vehicle manufacturers

permit caging the spring brake while the spring

brake is engaged.

Figure 44 - spring brake installation

The following instructions are for Bendix^®

CAUTION: Do not use brake chambers with seals that

brand piston-style actuators.

have a thickness less than 0.12 in. (3 mm). Use only

5.4.3

With the vehicle on a level surface and the wheels

actuators which are recommended by the vehicle

properly chocked, apply air to release the spring

manufacturer.

brakes (parking brakes) by using the dash-mounted

5.4.7

Install the brake chamber using new self-locking

air control valve. Back out the release bolt (Figure

nuts (EN ISO 10513). Alternately tighten both the

43, arrow “D”), using a maximum torque of 26 ft. lbs.

nuts step by step up to a final torque of 133 ± 7 ft. lbs

(35 N·m) to cage the air released spring force on

(180 ± 10 N·m). Bendix strongly recommends

the push rod.

that new nuts be used.

5.4.8

Re-connect the air hose(s) and be sure that each

hose is not twisted or in contact with moving vehicle

components. The air hose routing must allow for full

caliper travel. Note that for spring brake service

chambers the ports are indicated by: “11” Service

18/1

Brake Port and “12” Spring Brake Port

Figure 43 - Actuator spring caging and removal

Figure 45 - Port designations

5.4.4

Exhaust the air from the brake chambers by using

Note: Where a new spring brake chamber is being

the dash-mounted air control valve. With all air

installed, note that in some cases drain plugs are installed

pressure drained from the system, disconnect the

(See Figure 43, arrows marked “A”). Where drain plugs

air hoses from the brake chamber. While supporting

are present, after installation, remove whichever plug is

the brake chamber in position, remove and discard

at the lowest position. The selected drain hole must be

the brake chamber mounting nuts (Figure 45,

aligned downwards (or within ±30°) when installed on the

arrows marked “B”). Remove the brake chamber.

vehicle. In the case of spring brake chambers, install the

pads before uncaging the spring.

5.4.5

Re-installation. Before installing the brake chamber,

the actuator flange (See Figure 46, arrow “C”) must be

5.4.9

Before returning vehicle to service, with the system

cleaned and inspected. Consult the vehicle manual.

pressurized, using a soap solution, check for air

The spherical cup in the lever (19) must be greased

leakage. Minimal leakage in the area around the

with white grease (Part No.

14525 or K021964).

diaphragm is permitted (100 SCCM), and a one-inch

Add grease to the rubber gasket on the chamber.

bubble in one minute at the hose fitting is acceptable.

If abnormal leakage is detected, the diaphragm must

CAUTION: Do not use grease containing molybdenum

be replaced, or fitting adjusted, respectively.

disulfate.

5.4.6 The seal, as well as the push rod area, must be

clean and dry.

5.5

Tappet & boot Assemblies, and

44 Pad Retainer Pin

Inner Seal

tappet inner seal Replacement

Pad Retainer

5.5.1

CAUTION: Follow all safe maintenance

Spring Clip

13 Tappet

practices, including those listed on page two of

and

this document. Park the vehicle (by other means

Boot Assy

Washer

than the foundation brakes) on level ground and

chock the wheels.

In some cases, the technician will need to remove the caliper

161

Pad

carrier assembly from the vehicle. (See Section 5.3.) Note

Tappet

Assembly

Bushing

that new bolts (available from the vehicle manufacturer)

will be needed for re-installation.

Important: If the vehicle is equipped with spring brakes,

cage the spring brakes on all axles requiring work.

Tappet

Consult the vehicle manufacturer’s instructions as

and Boot

Assembly

necessary. This procedure may be carried out with

the air disc brake installed on, or removed from, the

vehicle. In cases where the caliper/carrier assembly

Shear

is removed from the vehicle, NEW fasteners must be

Adapter

used and properly torqued during re-installation. Use

161

only fasteners approved by the vehicle manufacturer.

Tappet

Adjuster Cap

Bushing

Note: This maintenance procedure uses specialized

22 Inner Seal

tools. The full Bendix air disc brake tool kit (K029164),

Figure 46 - ADB Exploded and section views

or Ken-Tool kit (80000), includes the complete set of

tools required for all permitted maintenance procedures.

5.5.2

Pad Removal: follow Sections 5.2.1-5.2.11 for

Alternately, for locations where only the tappet and boot

removal of the brake pads.

replacement procedures will be performed, the smaller

5.5.3

Inspect the Brake Rotor (See Section 4.4).

Bendix tool kit (K028829), or Ken-Tool kit (80001) will

Tappet and Boot Assembly (13) Removal

suffice. The DVD (BW7356) shows this procedure.

CAUTION: Never extend the tappet more than

Bendix

1.75 in. (44.5 mm). See Figure 47. Over-extending the

Number/

Description

Typical Tool View

tappet will result in the tappet losing engagement with

Ken-Tool

Number

the threads of the synchronizing mechanism. Since

the mechanism can only be set at the manufacturing

T1 / KT01

Cup

plant, the caliper/carrier assembly must be replaced

if this happens.

T2 / KT02

Handle for KT01 cup

Swivel assembly

(KT03-1 short body

T3 / KT03

+ KT03-2 brass disc

+ KT03-3 retaining

spring)

T4 / KT04

Long strut

T9 / KT09

Flange

Extend

Less Than

1.75 in.

T15 / KT015

Fork

(44.5 mm)

Figure 47 - permitted tappet extension

T24 / KT024

Black Nylon Disc

5.5.4

See Figure 47. Extend the tappets — less than

1.75 in. (44.5 mm) — by turning the shear adapter

(61) clockwise. A screwdriver (callout “B” in

Table 5 - tappet and boot replacement tools

Figure 47 inset) should be used to move the boot

5.5.9

Inspect the inner sealing face for damage. If

and allow the wedge fork (“A” in Figure 48) to be

damage is found that would cause the inner seals

inserted.

not to be able to seal properly, the caliper/carrier

assembly must be replaced. Clean the area around

CAUTION: Do not insert the screw driver more

the inner seal.

than ¼ inch. Take care not to damage the

inner sealing face (see arrow “X” in Figure 48).

5.5.10

Inspect the threaded tubes (16). See Figures 50

Gouges or grooves will prevent a good seal and

and 51. Extend the tubes, but by less than 1.75 in.

will require that the caliper be replaced.

(44.5 mm), by turning the shear adapter (61)

clockwise. Inspect the threads for rust, corrosion, or

damage etc. If there is evidence of damage to the

threads; significant rust; or corrosion, the caliper/

T15

carrier assembly must be replaced.

If the technician is working with the caliper on the

vehicle, the technician may place a new brake pad

(12) into the outboard gap to help avoid the loss

of thread engagement of the threaded tubes. See

Figure 50.

If the work is being carried out at a workbench, the

technician may insert a 2.76 in. (70 mm) spacer

(See callout “E” in Figure 51) into the caliper (1) to

help avoid the loss of thread engagement.

161

Figure 48 - wedge tool use

5.5.5

The tappet and boot assemblies (13) can then be

removed from the threaded tubes (16) by using the

wedge fork (T15). Be sure to orient the wedge tool

with the tapered side towards the tappet.

5.5.6

Remove the old tappet bushings (161).

5.5.7

Retract the threaded tubes by turning the shear

adapter (61) counter-clockwise.

5.5.8

See Figure 49. Carefully remove the inner seal

using one or two flat-blade screwdrivers as shown.

Caution: Do not insert the screwdrivers so far that

Figure 50 - Use of a new brake pad as a spacer

they come into contact with the threaded tubes.

Damage to the threaded tubes would require that

2.76 in.

the brake be replaced.

(70 mm)

Figure 51 - Use of a spacer (off-vehicle inspection)

5.5.11 For threads that are in good condition, grease the

threads with white grease (Part No.

14525 or

K021964). Before installing the replacement inner

seals (22), retract the threaded tubes by turning the

shear adapter (61) counter-clockwise.

Figure 49 - inner seal removal

Note: If the shear adapter fails while you are retracting

the threaded tubes, you may try again with another

(new) shear adapter. If this also fails, this indicates

that the adjuster mechanism is damaged and the

caliper must be replaced.

To install inner seals where the caliper is on the vehicle:

5.5.12 Position the replacement inner seal (22) over the

T9 / KT09

T4 / KT04

T3 / KT03

threaded tube (16). See Figures 52 and 53 for the

tools and installation arrangement used. Position

Figure 54 - On-vehicle inner seal installation tool

(L2)

the L1 (T3 + T9) with the short spacer (T3) in

position as shown in Figure 53. Guide the tool

over the end of the threaded tube (16). Install the

new inner seal (22) into position by rotating the

adjuster nut on the T3 portion of the tool, using an

open-ended wrench.

T9 / KT09

T3 / KT03

Figure 52 - On-vehicle inner seal tool (L1)

Figure 55 - Off-vehicle Inner seal installation

CAUTION: To confirm that the inner seal has been

correctly installed, begin to extend the threaded tubes

(16) by turning the shear adapter clockwise by 4-5

turns. Watch as the threaded tube extends. Inner seals

that are installed correctly will not rotate as the

threaded tube extends.

5.5.14 Note: Inspect the tappet/boot kit to determine if the

tappets supplied are already pre-greased (a plastic

cover should be present — be sure to remove the

cover when installing the tappet). Only in the case

of kits that are not pre-greased will the installer

need to apply grease to the tappets. In all cases,

the threaded portion of the tubes will need to be

Figure 53 - On-vehicle inner seal installation

greased. Retract the threaded tubes.

To install inner seals where the caliper has been

5.5.15 Install the new tappet bushing (161) onto the center

removed from the vehicle:

post of each threaded tube (16) by hand. By hand,

5.5.13 Position the replacement inner seal (22) over the

ease the tappet bushings onto the center post of

threaded tube (16). See Figures 54 and 55 for

the threaded tubes and they will snap into position.

the tools and installation arrangement used. The

5.5.16 The sealing seat in the caliper for tappet and boot

threaded tubes need to be retracted to allow the

assemblies (13) must be clean and free of grease.

tool to be inserted. Use the combination tool L2

Wipe the opening with a clean shop rag. Place a

(T4 + T3 + T9) with the long spacer (T4) as shown

tappet and boot assembly (13) in position over the

in Figure 55. Since the installation tool is guided by

center post and tappet bushing.

the center post of the threaded tube, advance the

tube a small amount to align the tool and the center

To install tappet and boot assemblies where the caliper

post. Install the new inner seal (22) into position

is on the vehicle:

by rotating the adjuster nut on the T4 portion of the

5.5.17 See Figures 56, 57 and 58. Use tool B1, comprising

tool using an open-ended wrench.

tools T1, T2, and T3 to press the boot into position.

The tool is then reversed, and the nylon disc (T24)

is inserted into the T1 “cup” (combination tool ‘B2’).

Holding the T1 handle, turn the nut on the T3 tool to

fully install the tappet onto the tappet bushing (161).

Figure 56 - On vehicle tappet and boot installation

Figure 59 - Off vehicle tappet boot installation tool

tool (B1 - with T24 installed, B2)

(B3, with T24 installed, B4)

161

Figure 57 - On vehicle tappet boot installation

Figure 60 - Off vehicle tappet boot installation

Figure 61 - Off vehicle tappet installation

Figure 58 - On vehicle tappet installation

5.5.19 Check that the tappets are firmly attached to the

To install tappet and boot assemblies where the caliper

bushings by gripping and pulling lightly on them by

is removed from the vehicle:

hand. Confirm that the tappets are able to rotate a

5.5.18 See Figures 59, 60 and 61. Retract the tappets,

small amount on the tappet bushings by grasping

as needed, in order to have room to install the

and turning them by hand. Finally, using a box-end

tappets. Use tool B3, comprising tools T1, T2, and

wrench on the shear adapter, extend the threaded

T3 to press the boot into position. The tool is then

tubes outward, and check that the boots are held

reversed, and the nylon disc (T24) is inserted into

in place. Retract the tappets.

the T1 “cup” (combination tool ‘B4’). Holding the

5.5.20 Re-install the caliper/carrier assembly, if it was

T1 handle, turn the nut on the T3 tool to fully seat

removed from the vehicle (See Section 5.3).

the tappet onto the tappet bushing (161).

5.5.21 Re-install the brake pads (See Section 5.2).

5.6 Guide pin and boot Assemblies

Vertical

Bolt Style

(with

bushing).

Bushing

(6)

Guide Pin

Ring

(4)

(58)

Inner

Horizontal

Boot

Mounting Bolt

Caliper Bolt

(9)

Style Shown:

(39)

Shear

See Inset Above

Adapter

for Vertical

Cap

(61)

Bolt Style (with

(68)

bushing).

Adjuster Cap

(Two alternate

Ring

caps supplied in kit)

(58)

(37)

Inner

Boot

(9)

Guide Pin

(5)

KIT CONTENTS

Item Description

Quantity

Guide Bushing

4 . . Guide Pin (Short)

(7)

5 . . Guide Pin (Long)

6 . . Bushing

7 . . Guide Bushing (Long)

Caliper Bolt

9 . . Inner Boot

(40)

Cap (Small)

Adjuster Cap (Two versions supplied)

Caliper Bolt (Short)

Cap

Caliper Bolt (Long)

(10)

Ring

Shear Adapter

Cap (Large)

(White grease is also supplied - not shown)

Figure 62 - Guide pin EXPLODED VIEW

The Bendix DVD (BW7356) shows this procedure.

These procedures are typically carried out with the

caliper/carrier removed from the vehicle (may be

5.6.1

CAUTION: Follow all safe maintenance

carried out with the air disc brake installed). In cases

practices, including those listed on page two of

where the caliper/carrier assembly is removed from

this document. Park the vehicle (by other means

the vehicle, NEW fasteners must be used and properly

than the foundation brakes) on level ground and

torqued during re-installation. Use only fasteners

chock the wheels.

approved by the vehicle manufacturer.

Important: If the vehicle is equipped with spring brakes,

Note: This maintenance procedure uses specialized

cage the spring brakes on all axles to be worked on.

tools. The full Bendix air disc brake tool kit (K029164),

Consult the vehicle manufacturer’s instructions as

or Ken-Tool kit (80000), includes the tools needed for the

necessary. For Bendix^® brand piston-style spring

guide pin and boot installation. See Table 6.

brake chambers, see Section 5.4.

Note that a smaller Bendix tool kit (K029107), or Ken-Tool

kit (80002) may be used where only the guide pins will be

serviced.

Bendix

Number/

Description

Typical Tool View

Description

Typical Tool View

Ken-Tool

Number

T05 / KT05

1-3/8 in. diameter disc

T14 / KT14

Brass nut

T06 / KT06

1-1/2 in. diameter disc

T16 / KT16

Dimpling tool

T07 / KT07

2 in. diameter sleeve

T20 / KT20

8 in. bolt

T08 / KT08

2-1/8 in. diameter disc

T21 / KT21

Half sleeve

T10 / KT10

8 in. bolt

T26 / KT26

Cap installation tool

T12 / KT12

3-7/8 in. long sleeve

T27 / KT27

Cap installation tool

Table 6 - Bendix^® ADb22X^™ air disc brake guide pin

T13 / KT13

10 in. bolt

and seals replacement tools. (a washer is also

included)

5.6.2

Remove the wheel. Refer to the vehicle manufac-

turer’s recommendations.

5.6.3

Remove the brake pads. See Section 5.2.

5.6.4

In most cases, the actuator should be removed. See

Section 5.4. In the case of spring brake actuators,

they should be caged before removing the brake

assembly.

Figure 63 - Punch guide

Figure 64 - guide pin cap

pin cap (10)

(10) hole

5.6.5

In nearly all cases, the air disc brake caliper/carrier

will need to be removed from the vehicle in order to

complete this procedure. See Section 5.3.

5.6.6

Place the brake on a workbench and, using a vice,

secure it by the carrier.

5.6.7

Use a small chisel or similar tool to punch a hole

close to the center of the guide pin cap (10) of the

Figure 65 - Pry to

Figure 66 - using small

short guide pin, taking care to only insert the chisel

remove guide pin cap (10)

chisel to remove guide

a small amount. Using the hole just made, pry the

pin cap (68)

cap off and discard. See Figures 63-65.

5.6.8

Remove the other cap (68) that covers the long

guide pin, by using a small chisel and hammer to

apply light blows to the cap, with the chisel aimed

away from the casting. See Figure 66. Discard

both caps.

5.6.9

Using a 14 mm hex

5.6.14 Turning the bolt at

bit socket, remove

the top, draw the

and discard the two

brass nut up, bring

caliper bolts (39) and

the brass bushing

(40). See Figure 67.

up and out of the

By hand, retract both

channel. Discard the

guide pins slightly

bushing.

and then remove

the caliper from the

Figure 67 - remove the

Figure 71 - remove the

carrier.

caliper bolts

long guide pin

The guide pins are now only held by the retaining

Caution: Keep the removal tool exactly aligned with the

rings (58).

guide pin channel to permit the bushing to be removed.

See Figure 72.

5.6.10

Remove the boot

retaining rings (58)

and the guide pins

T12 / KT12

(39) and (40). Use

a screwdriver to pry

Bushing (10)

out the inner boots

Removed

(9). See Figure 68.

T13 /

KT13

Discard the removed

items.

Figure 68 - remove the

retaining rings, guide

pins, and boots

5.6.11

Clean the caliper upper and lower surfaces around

Bushing

(10)

the bushings.

Installed

T14 / KT14

Grease the bolt prior to each use

Above: Incorrect

Above: Correct

Alignment

Figure 72 - Keep the correct alignment

Washer

T12 / KT12

T13 / KT13

T14 / KT14

5.6.15 Prepare to remove

the short guide pin

Figure 69 - brass Bushing removal tool

bushing by locating

the bushing (6) tab,

5.6.12 Prepare to remove the brass bushing used in the

long guide pin side. Assemble the long bolt (T13),

and using a small

chisel (narrower than

washer, and sleeve (T12) as in Figures 69 and 70.

the tab) or similar

5.6.13 Apply grease to the

tool, remove the tab

bolt and

— after

as shown in Figure

Figure 73 - remove the

tab that holds the

inserting through the

73, by striking low on

bushing in position

guide pin channel —

the base of the tab.

engage the brass

Remove the tab with a magnet and use a clean

nut (T14). Always

shop cloth to remove any excess debris. Note

double-check that

that in some cases, the tab may be in the opposite

the brass nut is

(outer) slot in the bore.

correctly in place in

Figure 70 - install the

removal tool

the bushing before

Grease the bolt prior to each use

beginning to extract

Washer

the bushing.

T20 / KT20

T14 / KT14

T21 / KT21

Figure 74 - short guide pin removal tool

5.6.16 Use the tool combination shown in Figures 74 and

5.6.20 Place a new brass guide bushing (7) on the dimpling

75 (comprising T14, T20, T21, and a washer) to

tool (T16) and insert it into the caliper bore.

remove the bushing (6). Screw nut (T14) onto the

assembly by hand, then tighten the bolt (T20) using

a box end wrench to draw out the bushing. Discard

the removed bushing, and verify that the bore is

clean by wiping with a shop cloth.

T14/

KT14

T20

Washer

T21

View

“A”

“C”

“B”

Figure 77 - View “a” and “b”: draw the brass bushing

into position. View “C”: lock the bushing into

T14

position

5.6.21

Check that the flange (T08) is in an upright position

at the top of the caliper recess as you draw the brass

Figure 75 - sectional view: short guide pin bushing

removal

bushing (7) up, by turning the brass nut (T14), until

the dimpling tool bottoms on the caliper. When it

Installation of the Fixed Guide Pin Brass

reaches the correct position, the brass bushing

Bushing

extends out of the guide pin channel 0.039 in.

(1 mm.).

5.6.17 Clean the caliper upper and lower surfaces around

the bushings.

5.6.22

With the dimpling tool (T16) in position, tighten the

5.6.18 Clamp the carrier in a vise so that the guide channel

screw in its base until it contacts the dimpling screw

housing. The movement of this screw forces three

is vertically oriented.

points outwards, leaving indentations in the brass

Grease the bolt prior to each use

bushing. See Figure 77, view “C”.

T13 / KT13

Washer

5.6.23

Unscrew the dimpling screw out approximately 0.75

inches (20 mm.). Loosen the brass nut (T14) and

rotate the dimpling tool (T16) 60 degrees. Repeat

the dimpling process by tightening the brass nut

T14 / KT14

T08 / KT08

T16 / KT16

(T14) and then tighten the dimpling screw until it

contacts the dimpling screw housing. Back out the

Figure 76 - Long guide pin bushing installation and

dimpling tool

dimpling screw approximately 0.75 inches (20 mm.).

The brass bushing (7) is now held in position by the

5.6.19 Place the washer and thread the brass nut (T14) on

six dimples made by the tool.

to the bolt (T13) followed by the flange (T08). See

Figure 76.

5.6.24

Remove the installation tools and check the brass

bushing (7), removing any burrs, being careful not

to leave any metal filings in the bushing. Coat the

inside of the bushing with the white grease included

in the kit.

Installation of the Floating Guide Pin Bushing

5.6.25 To install the bushing (6) into the short guide pin

side, first inspect the bore for corrosion, damage

etc. Clean as necessary.

5.6.26 Place the new bush-

surface of the caliper is damaged, replace the

ing (6) in position so

caliper.

that when drawn

Washer

Grease the bolt prior to each use

into position, the

tab will align with

the slot in the cast-

ing. With the tab

aligned, place tool

T10 / KT10

(T14) over the bush-

T08 / KT08

T07 / KT07

Figure 78 - Position the

ing and tap lightly. To

new bushing

Figure 81 - short guide pin boot installation tool

position the bushing,

see Figure 78.

5.6.31

See Figure 82. Place

a boot into the in-

T20 / KT20

Washer

Grease the bolt prior to each use

stallation tool (T7),

making sure that

the inner bellows

are arranged close

to the side walls of

T14 / KT14

T05 / KT05

T06 / KT06

T08 / KT08

the tool and will not

be damaged dur-

Figure 82 - Position

Figure 79 - short guide pin bushing installation tool

the new boot in the

ing installation. Also

installation tool (T7)

5.6.27

Use the tool combination shown in Figure 79 to

check that the outer

draw the bushing (6) into the caliper. See also

edge of the boot

Figure 80, to see the orientation (with tool T14 at

rests on the front

the top). Hand tighten the nut (T14) into position.

edge of the tool.

Then tighten the bolt (T20) using a box end wrench

or socket to draw the bushing (6) into the caliper

until the bushing (6) contacts the machined step in

5.6.32

Using 70 in. lbs. (8 N·m) of torque maximum, tighten

the bore. Remove the tool.

bolt (T10) to install the inner boot.

5.6.33

Repeat the installation procedure for the second

inner boot.

5.6.34

Check that the boots are held securely in place and

that no damage occurred during installation.

5.6.35

See Figure 83. To

install the guide

T14

pins, first lubricate

both guide pins with

the white grease

Bushing Stop

supplied. Insert the

T08

guide pins into their

respective bores

T06

with the grooved end

Figure 83 - Place the

T05

retaining ring onto the

towards the bellows.

groove in the guide pin

T20

Washer

Fit the lip in the end of the inner boots (8) into the

groove of the guide pins. Push on each ring (7)

Figure 80 - guide pin bushing installation

ensuring that the boot (9) is engaged onto the end

5.6.28 Using a punch, bend the tab into the groove by

of the guide pins (5 or 6).

aligning the punch with the upper part of the tab

and tapping the punch with a hammer.

5.6.36

With the caliper resting on a bench, slide the carrier

into place with a slight rocking motion, taking care

5.6.29 Coat the inside of the bushing (6) with a light coat

that as you do so, the inner boots and guide pins

of the white grease included in the kit.

are seated in their proper place on the carrier.

5.6.30 Install the two identical inner boots (9) by first

5.6.37

Identify the two caliper bolts (39) and (40). With the

cleaning the area where the inner boots will be

shorter bolt placed in the floating pin bushing (4), and

installed and inspect for corrosion. If the sealing

the longer bolt placed in the fixed pin bushing (5),

begin to tighten the bolts. With the caliper/carrier

5.6.40

Select one cap to

in a vice, continue installing the bolts to a torque of

install. Using the

133 ft. lbs. (180 N·m). Finally, tighten each bolt an

correct press-in

additional 90º (ninety degrees).

tool — the smaller

cap (10) installs in the

Installation of the Guide Pin Caps

long guide pin side

using tool (T26), and

5.6.38

See Figure 84. Place

BOOT

the larger cap (68)

the caliper/carrier as-

COMPRESSED

installs in the short

Figure 85 - bootS must

sembly on a bench

BE COMPRESSED FULLY

guide pin side using

so that the inner

DURING CAP installation

tool (T27) — place

boots are fully com-

the cap in position,

pressed, check that

using the machined

the bores are clean

channel in the caliper

and dry (e.g. free

Figure 84 - bootS must

to assist in centering

from lubrication).

BE COMPRESSED FULLY

the tool.

DURING CAP installation

Use a hammer to tap the cap into position. See

Note: It is important that the inner boots are fully

Figure 85. Note that the tool needs to remain

compressed during this procedure to ensure that

perpendicular to the channel to prevent damage

the least amount of air is retained within the guide

during installation. Note that, after installation, the

pin channel. If too much air is trapped, the bellows

smaller cap (10) extends 0.08 in. (2 mm.), and the

can potentially be damaged during the operation of

larger cap (68) extends 0.61 in. (15.5 mm.).

the brake. It is also important that the technician

double-check that the retaining rings remain in their

Repeat for the second cap.

correct position during this procedure.

5.6.41

Check that the guide pins move freely when the

carrier is moved laterally, and that air is not trapped

5.6.39

Clean the two caps, and check that the caliper

surfaces where the caps will be installed are clean

within the inner boots, and that the boots (9) and

ring (58) are in the proper position before continuing

and have no signs of damage.

with the installation.

5.6.42

Install the caliper/carrier (See Section 5.3).

5.6.43

Install the brake chamber (See Section 5.4).

5.6.44

Install the brake pads (See Section 5.2).

5.7 Bendix^® splined disc^® Hub rotor

DRIVE HUB

STEER HUB

Wheel Studs

Intermediate Elements

Hub

(Spacers)

Hub

Intermediate Elements

ID Label

Spring Elements

(Spacers)

(Retention

Spring Elements

ID Label

Brackets)

(Retention

Brackets)

ABS Tone

Wheel

& Fasteners

ABS Tone Wheel

(press on)

Splined Disc Rotor

Above: Splined Disc Rotor on Aluminum Drive Hub

Above: Splined Disc Rotor on Aluminum Steer Hub

Figure 86 - Splined disc rotor examples - EXPLODED Views

Bendix^® Splined Disc^® Hub Rotors are designed to assist

Bendix Air Disc Brakes are precision-engineered braking

vehicle maintenance by typically allowing the rotor to be

mechanisms. The “friction couple” braking characteristics

serviced without requiring the entire hub/rotor assembly

have been carefully optimized and the rotor design and

be replaced.

materials have been matched with special formulation

brake pads for optimal performance, therefore use only

Periodic inspection of the Splined Disc attachment

genuine Bendix^® brand parts and brake pads.

hardware is recommended to ensure optimum braking

performance. Bendix recommends verifying the torque on

Rotor Replacement

the spring element fasteners whenever a brake inspection

5.7.1

Before removing the brake pads it is strongly

is performed.

recommended that the air disc brake adjuster

NOTE: Anytime that the entire hub/rotor assembly

mechanism be checked for correct operation (See

is removed, Bendix recommends that the wheel seal

Section 4.1). When replacing brake pads, Bendix

also be replaced at the same time, using a high-

strongly recommends that the pads be replaced as

temperature seal. Follow the wheel seal and/or

an axle set.

vehicle manufacturer's guidelines for full installation

5.7.2

Refer to the vehicle manufacturer’s recommendations

instructions. Adjust the bearings and refill bearing

and release (or cage) spring brakes and remove the

oil to vehicle manufacturer's specifications.

wheel.

When replacing a Splined Disc Rotor, Bendix strongly

5.7.3

Remove the pads (See Section 5.2).

recommends that the brake pads be replaced (as an

5.7.4

Remove the air disc brake (See Section 5.3).

axle set.) Contact 1-800-AIR-BRAKE for appropriate

5.7.5

Remove the hub rotor assembly.

brake pad kit. Rotor replacement necessitates the

removal of the pads.

Note: Follow the vehicle manufacturer's guidelines for

removal of the wheel hub and rotor assembly from the

CAUTION: Follow all safe maintenance practices,

vehicle in lieu of these instructions, where available.

including those listed on page two of this document.

Park the vehicle (by other means than the foundation

Caution: Be sure to secure both the rotor and hub

brakes) on level ground and chock the wheels. Also

before removing the retention clips.

read the vehicle manufacturer's recommendations.

5.7.6

Remove and discard the ten spring elements.

When installing pads, where appropriate, use heavy

duty gloves and always keep fingers away from

5.7.7

On drive axles, the ABS tone ring must also be

potential pinch hazard areas.

removed. (See Figure 86.) Retain for re-installation.

5.7.8

Use suitable hand tools to remove the intermediate

elements (spacers). Remove all the right-hand

intermediate elements (spacers) of each set first

and then the rotor can be turned slightly to release

the remaining intermediate elements (spacers).

be corrected with proper installation of new rotor

In all cases, take care not to damage the hub and

retaining hardware.

its teeth. Remove and discard the intermediate

elements (spacers) and retention clips attaching

the rotor. Discard the rotor.

5.7.9

Following industry standards, clean and inspect the

hub before installing the rotor. Look for corrosion

and/or damage to the hub and inspect the wheel

speed tone ring. Where necessary, consult the hub

manufacturer's guidelines for more details.

B-B

KEY

1 - Wheel Hub

2 - Splined Disc Rotor

3 - Intermediate Elements (Spacers)

Figure 89 - installing Intermediate Elements

(spacers)

KEY

1 - Wheel Hub

2 - Splined Disc Rotor

3 - Intermediate Element (Spacer)

4 - Spring Element (Fastener), including retention clips

Figure 87 - Rotor with cross-section view

Figure 90 - Intermediate Elements (Spacers) installed

5.7.11 Install the ten new spring elements included in the

kit in an evenly-distributed cross-pattern sequence.

Torque to 22.1 ft. lbs. (30 N·m.)

5.7.12 Where the tone ring was removed during step 5.7.7,

Figure 88 - Rotor installation

re-install the tone ring. Use a professional grade

fastener compound, such as Loctite blue 242, on

ROTOR INSTALLATION

the fasteners. Torque to 19-22 in. lbs. (2.1-2.5 N·m.)

5.7.10 See Figures 87 through 91. Place the rotor into

5.7.13 Re-install the hub rotor assembly using a new

position on the hub. Install the new intermediate

high-temperature wheel seal, following the vehicle

elements (spacers) as shown in Figure 89. With

manufacturer’s instructions.

all the intermediate elements (spacers) correctly

inserted into position, verify that the gap between

the intermediate elements (spacers) and the wheel

hub does not exceed 0.015 in (0.4 mm). If a gap is

found that exceeds this maximum value, verify the

installation of new intermediate elements (spacers).

Replace the wheel hub if the excess gap cannot

5.7.14 Re-install the air disc brake (See Section 5.3).

Supporting the air disc brake by all necessary

means, attach the brake to the anchor plate

using six bolts and washers as required (Bendix

recommends the original bolts not be re-used).

Torque to vehicle manufacturer's specifications.

If torque values and bolts are not specified by the

vehicle manufacturer, then torque according to the

chart below. Be sure to select bolts with the same

thread pitch, length and grade as originally provided

from vehicle manufacturer.

5.7.15 Reinstall the brake pads (See Section 5.2).

Figure 91 - fasteners installed

Air Disc Brake Attachment Hardware

Torque Plate Manufacturer

Fastener

Torque

Bendix Axial

Carrier Torque Plate

Fastener: M20 x 2.5 x 60 mm Class 10.9

Washer: Requires a THROUGH

Use the manufacturer’s recommendations.

HARDENED 3 mm (minimum thickness) for

If unavailable, use phosphate

each bolt.¹If the vehicle is using a Bendix

and oil finish fastener.

manufactured Axial Anchor Plate, with a

thickness of 1.14 in. (29 mm) where these

Pre-Torque: 20-60 ft-lbf [27-81 N·m]

bolts are assembled, then a bolt with an

Final Torque: 350-400 ft-lbf [475-542 N·m]

overall length of 2.36 in. (60 mm) will meet

these requirements

Bendix Vertical

Carrier Torque Plate

Use the manufacturer’s recommendations.

Fastener: M16 x 2.0 x 110 mm, Class 10.9

If unavailable, use plain and oil finish fastener.

Washer: None required.

Torque: 200-220 ft-lbf [271-298 N·m]

Fastener: M20 x 2.5 x L Class 10.9

Use the manufacturer’s recommendations.

Length determination:

If unavailable, use phosphate

L = Torque Plate (TP) thickness + Carrier

and oil finish fastener:

engagement + Washer thickness

Trailer Torque Plate

Pre-Torque: 20-60 ft-lbf [27-81 N·m]

L_min = TP thickness + 24 mm + 3 mm

Final Torque: 350-400 ft-lbf [475-542 N·m]

L_max = TP thickness + 29 mm + 3 mm

Washer: Requires THROUGH HARDENED

3 mm (minimum thickness) for each bolt.¹

Footnote 1 CAUTION: The washer outside diameter must be less than 1.5 in (37.5 mm).

Recommended washers conform to DIN125-21-300HV, ISO7089-20-300HV, or ISO7090-20-300HV.

Table 7 - Torque plate fasteners and torque recommendations (see Manufacturer’S recommendations)

Service Data Index

Section One: Air Disc Brake Overview

Safe Maintenance Practices

Section Two: Preventive Maintenance Schedule and Wheel-On Inspections .6

2.0

Preventive Maintenance

2.1

Brake Pad And Rotor Inspections

2.2

Running Clearance Quick Inspection

Section Three: Troubleshooting Procedure Flowchart

Section Four: Wheel-Off Maintenance Inspections

4.0

Wheel-Off Inspections

4.1

Caliper Movement Test

4.2

Adjuster Mechanism Inspection

4.3

Inspect The Brake Pads

4.4

Inspect The Rotor

4.5

Guide Pin Bearing Inspection

4.6

Tappet And Boot Assembly Inspection

Section Five: Maintenance Kits And Procedures

5.0

Maintenance Kits

5.0.1 General Information About Bendix Air Disc Brake Maintenance

5.1

Air Disc Brake Shield Kit

5.2

Pad Replacement

5.3

Caliper/Carrier/Actuator Assembly

5.4

Spring or Service Brake

5.5

Tappet & Boot Assemblies, and Tappet Inner Seal Replacement

5.6

Guide Pin and Boot Assemblies

5.7

Bendix^® Splined Disc^® Hub Rotor

Contacting Bendix