Zoomlion Scissor lift ZS4555HD, ZS4045HD, ZS3246HD, ZS2632HD, ZS2032HD, ZS1930HD, ZS1530DC. Service and Maintenance Manual

SECTION 4 HYDRAULIC SYSTEM MAINTENANCE

4.1 Inspection and Maintenance of Hydraulic System

4.1.1 Routine inspection of hydraulic system

In order to keep the hydraulic system in good working condition for a long time, the hydraulic system

needs to be maintained and maintained on time.The following are some routine inspections and

maintenance:

Table 4-1 Hydraulic system maintenance intervals

Inspection Intervals (Working hours)

Inspection & maintenance

No.

Remark

items

100

250

500

1000

2000

Hydraulic

Oil

Quantity

★

Inspection

Hydraulic

oil

sediment

★

inspection

Check for Clogging of Exhaust

★

Cap of Hydraulic Oil Tank

Oil leakage from hydraulic

motor and pump,

★

abnormal sound inspection

Oil leakage inspection of

★

hydraulic valve

4-1

Table 4-2 Schedule replacement of hydraulic system parts

Replacement Intervals

Every

Once every 24

Mounting

No.

Replacement parts

First time

500H

1000H

months

position

50 H/30 D

/6 Months

/12 M

(not working)

★

Filter Element for

Oil circuit

★

Oil Return Filter

control

(First time)

Filter Element for

★

Hydraulic

Exhaust Cover of

★

tank

(First time)

Hydraulic Oil Tank

Replace Hydraulic

Mandatory

Oil

replacement

In the routine maintenance of the hydraulic system, the following points should be noted:

The functions of hydraulic oil in hydraulic system is transferring pressure, lubrication, cooling and

sealing. The improper selection of hydraulic oil is the main reason for the early failure and durability

decline of the hydraulic system. The hydraulic oil should be selected according to per requirements.

When the use of substitute oil is needed in special circumstances, the property of the hydraulic oil

should be as good as that of the original one. Different specifications of hydraulic oil cannot be

mixed up, in case the hydraulic oil produced chemical reaction, or property change. If the hydraulic

oil is dark brown, creamy or smelly, it cannot be used.

To prevent solid impurities from mixing into the hydraulic system, the cleanness of hydraulic oil is

the lifeblood of the hydraulic system. There are many precision couplings in the hydraulic system,

some of them are provided with damping holes or gaps, etc. If the solid impurity intrudes, it will

cause the precision couplings parts strain, block, oil duct jam and so on, which will endanger the safe

operation of the hydraulic system. The invasion routes of common solid impurities are:

1) Dirty hydraulic oils.

2) Dirty oil charging tool.

3) Carelessness during oil charge or maintenance.

4) Hydraulic elements debris.

Prevent air and water intrusion into hydraulic systems. At normal temperature and pressure, the air

will come out from the oil when the volume ratio of air in hydraulic oil is 6%~ 8% as the pressure is

lowered. The bubble rupture causes "cavitation" to the hydraulic element which produces noise. On

the one hand, air also oxidizes the hydraulic oil and accelerates its deterioration. On the other hand,

a large amount of air into the oil will make the "cavitation" phenomenon worse, and the compression

4-2

of hydraulic oil increases, which give rise to unstable operation, low work efficiency, "crawling"

actuating element and other adverse consequences. The following points should therefore be noted

in preventing air intrusion:

After maintenance and oil change, the air in the system is excluded as required.

The seal of the pump driving shaft shall be good. When replacing the oil seal, use the "two-lip"

quality oil seal, and "one-lip" oil seal is not allowed, because the "one-lip" oil seal can only one-

way sealing oil, and do not have the function of sealing gas.

The suction pipe of the hydraulic oil pump must not come out from the oil surface, and the

suction pipe must be well sealed.

Tighten the lid when oil storage barrel not in use and preferably place it upside down.

Hydraulic oil with high water content should have multi-filtration, and dried filter paper should

be used for each filtration.

Oil charging tools should be clean and hydraulic oil must be filtered before charging. Do not

remove the filter at the port of the hydraulic oil tank for faster filling up.

Oil supplier shall wear clean gloves and work clothes.

The cleaning oil of the hydraulic system must use the same hydraulic oil as that used in the

system and the cleaning oil temperature should be between 45 ℃/113℉ and 80 ℃/176℉

and the impurity in the system is carried away with the large flow as far as possible. The

hydraulic system should be cleaned more than three times, and all cleaning oil should be let out

from the system after each cleaning. Clean the filter after system cleaning, replace the filter

element and fill up new oil.

Clean the dirt around the hydraulic oil tank lid before removing the lid, then loosen the lid and

remove any debris remaining in the joint position. When remove the hydraulic oil tank lid, inspection

hole, hydraulic oil hoses, the exposure of hydraulic system oil pipe to dust should be avoided. Parts

must be cleaned thoroughly before opening. When scrubbing materials and hammers are used, it is

advisable to use special hammers with rubber on strike side and scrubbing materials with no losses

particle. Clean the hydraulic components and hoses carefully and wind-dry them with high pressure.

Choose the original filter element with good packing. Clean the inside of filter case carefully before

installing the filter element, and filling up new oil and cleaning the filter at one time.

4.1.2 Hydraulic oil tank

4.1.2.1 Inspection of hydraulic oil tank

The side of the hydraulic oil tank is with scale, and the corresponding scale has the corresponding capacity

value. Be sure to check the oil level of the hydraulic oil tank before the motor is started. When scissor

structure in retracted position, the oil level of the tank should not be lower than the required level and also

not higher than the maximum level. When the work platform is placed horizontally, if the oil level is lower

4-3

than the minimum level, which indicates there is not enough oil in the hydraulic system, please fill up

enough hydraulic oil before starting the machine.

If the amount of oil in the tank is found to be increased too fast, it indicates that there is a leak in the

pipeline or hydraulic components, check the hydraulic lines and components, find the leak point and

prevent it from leaking before starting the engine.

When hydraulic oil is at low temperature of (below 20 ℃/68℉), fluidity of hydraulic oil is poor, and

hydraulic components will be damaged due to over-urgent operation under this condition. the hydraulic

oil will deteriorate more quickly if the temperature is too high (above 80℃/176℉), and the service life

of the hydraulic components will be shortened. Therefore, after starting the engine in cold temperature

environment, full preheating should be carried out to make the hydraulic oil temperature reach 20℃/68

℉ or so.

a) If hydraulic oil is found to be abnormal during inspection, no matter how long the machine runs, the

hydraulic oil must be replaced. If the hydraulic oil contamination or deterioration time is too short,

the cause should be identified first, and then change the oil.

b) In the course of maintenance, it is found that the amount of hydraulic oil is not enough, the oil to be

replenished must be the same as that in the original tank, and the quantity specified in the oil leveler

should be replenished.

4.1.2.2 Replace return oil filter

In order to replace the filter element, the filter must be removed. The replacement steps are as follows:

a) The scissor structure is completely retracted and the motor is switched off. The system has to

decompress.

b) Using the tool to remove the lower part of the filter (as shown in Figure 4-1).

Hydraulic Oil

Figure 4-1 Filter position

4-4

c) Loosen the lower part of the filter and remove the filter element. Dispose of filter elements in an

environmentally friendly manner.

d) Install the new filter on the filter seat.Pay attention to the O-ring during installation.

Replace the return oil filter after 50 working hours after the first maintenance of the hydraulic system.

Then the filter element of the return oil filter should be replaced every 500 working hours.

When replacing the filter element, please be careful not to reverse the filter inlet and outlet ports,

otherwise it will cause serious consequences.

4.1.2.3 Replace exhaust hydraulic oil

In the hydraulic system, the exhaust cap of the tank should be checked on time. The inspection should be

done after adding hydraulic oil every time. The contamination should be cleaned up in time, and the

damaged part should be replaced.

4.1.2.4 Replace hydraulic oil

When delivery, the hydraulic oil tank has been filled up with hydraulic oil (oil type) according to customer

or environment requirement.

Before changing the hydraulic oil, the work platform must be in horizontal position. Oil change steps are

as follows:

a) Switch off the motor and depressurize the hydraulic system.

b) Install the oil exit pipe on the plug of the hydraulic tank and pump the oil into a suitable container.

Take care to dispose of waste oil in an environmental friendly manner.

c) To clean the tank with a chemical cleaning agent with pollution grade of solid particle no more than

18/15, and after cleaning and drying, rinse with a new hydraulic oil of pollution grade of solid

particles no more than 18/15, then release the cleaning oil and charge new hydraulic oil into the

hydraulic tank.

d) Start the motor to run at low speed, and oil pump start working, then operate each mechanism. The

new hydraulic oil discharges the old oil of each circuit of the system gradually, and the old oil

discharged is not allowed to flow back to the hydraulic oil tank. When changing oil in each circuit,

new oil should be added constantly into the hydraulic oil to prevent the oil pump from emptying.

e) Install the oil plug, and prepare all the components in the initial working condition, then replenish

the hydraulic oil to the specified oil level.

Ensure all stop valves and quick couplings are open. All stop valves and quick couplings must be

opened to keep the whole oil line open.

4-5

a) Hydraulic oil should not be used for more than 24 months, and after 24 months, the oil is not allowed

to be used even after filtration.

b) Filter or replace hydraulic oil whenever it is found to be seriously contaminated.

c) Select appropriate hydraulic oil according to ambient temperature.

d) Hydraulic oil of different brands cannot be mixed with each other.

e) When changing oil, wash off all the old oil and take care not to mix the sand, dust, etc. with the oil

tank.

When changing the oil in each circuit, pay attention to constantly replenishing the hydraulic fluid

with new oil to prevent the pump from emptying.

g) When use the machine at cold area, it is important to have no-load start-up after reaching minimum

start-up temperature. After the no-load operation, the system has reached its lowest operating

temperature and then slowly increase the load and keep the system running above the lowest

operating temperature.

h) Be environmentally friendly when dealing with hydraulic fluids.

4.1.3 Hydraulic system air exhaust

Usually, the hydraulic system will have air exhaust automatically. Hence, the motor runs at low speed and

low pressure and slowly operate individual cylinders several times back and forth until the air is

completely exhausted.

4.1.4 Check hydraulic system line breakage

The rubber pipe placed in the bend of the hydraulic tray is prone to friction damage. Check and ensure it

is in good condition. Replace it if it is damaged. Make sure that all pipelines and hoses are kept at a

sufficient distance in transitions (such as the corners of hydraulic pallets) so that there is no friction in

laying.

4.1.5 Hydraulic cylinder inspection

The cylinder of each auxiliary device should be inspected periodically. The inspection items shall include:

a) Check for scratches on the piston rod.

b) Check the seal between the piston rod and the cylinder for oil leakage, while doing corresponding

auxiliary action.

c) Check whether the piston rod of the longer stroke cylinder is bent.

d) If there are oil leaks between the piston rod and the cylinder, the manufacturer or professional

maintenance personnel should be called to perform the repair. Every effort should be made to prevent

4-6

the piston rod from being scratched.

When the piston rod is severely scratched and caused oil leakage, the manufacturer or professional

maintenance personnel should be repaired. If it cannot be repaired, it should be replaced. When the

piston rod is bent and cannot work properly, the manufacturer or professional maintenance personnel

should be contacted to replace the cylinder.

When using and transporting hydraulic cylinders, the following aspects should be noted:

The hydraulic cylinder should be packed during storage and transportation, and protection shall be

added to the oil-joint face and the exposed part of the piston rod.

Collision should be avoided during storage and transport..

The lifting shall be secured so as not to drop and scratch.

Before removing the hydraulic cylinder, the pressure in the hydraulic cylinder circuit shall be reduced

to zero.

When disassembling, prevent damage to the components of the hydraulic cylinder.

Protect the outer surface of the piston rod, prevent bumps and scratches on the seal, and regularly

clean the oil cylinder and the exposed piston rod of the dust-proof ring area. Prevent the non-easy-

to-clean dirt on the piston rod surface from getting into the cylinder which could damage the piston,

cylinder or seal.

Regular inspection of the connection parts such as threads, bolts and immediately fastening if found

loose.

Frequent lubrication of the joint to prevent corrosion or abnormal wear without lubricant.

4.1.6 Hydraulic hose inspection

All hydraulic hoses need to be checked periodically for damage. During these visual inspection, all

damaged hoses should be replaced immediately, even if very minor damage is found.

Possible problems with hydraulic hoses:

a) Damage to the outer layer, e.g. abrasion, notches, cracks, etc..

b) Ageing of the outer layer material and the formation of cracks.

c) Deformations that do not correspond to the natural shape of the hose, such as surface relaxation,

severe extrusion, distortion, etc..

d) Leakage.

e) Failure to comply with installation and positioning requirements (refer to the below matters needed

attention of installation of hydraulic hoses).

Damage to the fixtures of the hose unit.

4-7

g) Corrosion, deformation or damage of hose unit.

h) Exceeding storage time or service life.

Even if no damage is found, the hoses must be replaced every six years (including a maximum of two

years of storage time) at the latest. For use or storage life, it should be based on the manufacturing date

on the hydraulic hose.

When installing hydraulic hose, the following should be noted:

1) Avoid hose distortion:

The bearing pressure of the hose is lowered when it is twisted.

The twisted hose also loosens the connection to the connector.

7° twist to hose reduces hose life by 10%.

Correct

Incorrect

Figure 4-2 Prevent hose twisting

1) To increase the bending radius sufficiently:

To ensure smooth flow of fluid, effectively avoid hose damage.

Too small bending radius will greatly reduce the life of the hose assembly.

Incorrect

Correct

Figure 4-3 Proper bending radius

1) Use elbow and other connectors if necessary:

Too long hose assembly can be avoided.

To ensure that the installation is tidy and the maintenance is convenient in the future.

4-8

Table 4-3 Hydraulic driven platform control valves

No.

Item

Function

Torque

Overflow valve

System main pressure

42Nm/31ft-lbs

Pressure test joint

Measuring pressure

35Nm/26ft-lbs

Compensation valve

priority flow dividing

40Nm/29ft-lbs

Overflow valve

Lifting pressure

42Nm/31ft-lbs

Overflow valve

Steering pressure

42Nm/31ft-lbs

Solenoid coil nuts

Locking electromagnet

4Nm/3ft-lbs

Solenoid valve

Forward/Backward

40Nm/29ft-lbs

Solenoid valve

Fast/Slow speed

40Nm/29ft-lbs

Balance valve

Stable driving

72Nm/53ft-lbs

Balance valve

Stable driving

72Nm/53ft-lbs

Solenoid valve

Steering left/right

40Nm/29ft-lbs

Solenoid valve

Lifting/Lowering

40Nm/29ft-lbs

4-11

c) ZS1530DC/ZS1530DC-Li power unit.

Figure 4-10 ZS1530DC/ZS1530DC-Li power unit

Table 4-5 ZS1530DC/ZS1530DC-Li power unit

No.

Item

Function

Torque

Precipitation of impurities,

Oil tank

——

storage, cooling oil

Overflow valve

Lifting pressure

29Nm/22ft-lbs

Overflow valve

Steering pressure

29Nm/22ft-lbs

Solenoid valve

Steering left/right

29Nm/22ft-lbs

Motor

Power source

——

Solenoid valve

Lifting/Lowering

29Nm/22ft-lbs

Pressure test joint

Measuring pressure

35Nm/26ft-lbs

Tank cap

Prevent/refuel

——

Exhaust cover

Ventilation

——

4-13

4.1.8 Hydraulic system pressure adjusting

When adjusting the pressure, the operation handle is connected to the lower control system, and the

pressure regulator operates on the ground.Before adjusting the pressure, make sure that the oil in the tank

is within the specified range.

4.1.8.1 Main pressure adjusting

For

ZS4555HD/ZS4555HD-Li/ZS4045HD/ZS4045HD-Li/ZS3246HD/ZS3246HD-Li/ZS2632HD/

ZS2632HD-Li/ZS2032HD/ZS2032HD-Li/ZS1930HD/ZS1930HD-Li,overflow valve is shown in 4-13,

see the pressure adjusting steps as follows:

a) Remove the operating handle from the platform and open the hydraulic tray, and connect the

operating handle to the lower control line.

b) Connect a pressure gauge with a measuring range of 0 to 5000 psi or 0 to 350 bar to the pressure

measuring connector.

c) Loosen the relief valve lock nut.

d) Insert the key to open the lower control system.

e) Hold down the function switch, move the joystick forward or backward while observing the reading

on the pressure gauge, and record the pressure value.

When adjusting the pressure, insert an Allen wrench into the adjusting nut, and turn clockwise to

increase the pressure, and turn it counterclockwise to decrease the pressure.

g) After the pressure adjustment is completed, tighten the relief valve lock nut, remove the pressure

gauge, and connect the operating handle to the upper control system.

Figure 4-13 Main overflow valve diagram

4-16

a) The set pressure must not be higher than the specified pressure, otherwise the components will be

damaged and even personal safety will be endangered.

b) The setting pressure cannot be less than the specified pressure, otherwise it will cause difficulty in

climbing.

c) Do not change the set pressure at will, otherwise it will affect the normal operation of the equipment.

4.1.8.2 Steering pressure adjusting

Adjusting steps:

a) Remove the operating handle from the platform and open the hydraulic tray, and connect the

operating handle to the lower control line.

b) Connect a pressure gauge with a measuring range of 0 to 5000 psi or 0 to 350 bar to the pressure

measuring connector.

c) Loosen the relief valve lock nut.

d) Insert the key to open the lower control system.

e) Hold down the function switch to make the tire turn left or right to the maximum angle while

observing the reading on the pressure gauge and recording the pressure value.

When adjusting the pressure, insert an Allen wrench into the adjusting nut, and turn clockwise to

increase the pressure, and turn it counterclockwise to decrease the pressure.

g) After the pressure adjustment is completed, tighten the relief valve lock nut, remove the pressure

gauge, and connect the operating handle to the upper control system.

For

ZS4555HD/ZS4045HD/ZS3246HD/ZS2632HD/ZS2032HD/ZS1930HD/ZS4555HD-

Li/ZS4045HD-Li/ZS3246HD-Li/ZS2632HD-Li/ZS2032HD-Li/ZS1930HD-Li, steering relief valve is

shown in fig.4-14.

Figure 4-14 Steering relief valve diagram

4-17

For ZS4555DC/ZS4045DC/ZS3246DC/ZS2632DC/ZS2032DC/ZS1930DC/ZS4555DC-Li/ZS4045DC-

Li/ZS3246DC-Li/ZS2632DC-Li/ZS2032DC-Li/ZS1930DC-Li, steering relief valve is shown Fig. 4-15.

1.Pressure measuring joint

2. steering relief valve

Figure 4-15 Steering relief valve diagram

For ZS1530DC/ZS1530DC-Li, steering relief valve is shown in Fig.4-16.

1.Pressure measuring joint

2. steering relief valve

Figure 4-16 Steering relief valve diagram

a) The set pressure must not be higher than the specified pressure, otherwise the components will be

damaged and even personal safety will be endangered.

b) The setting pressure cannot be less than the specified pressure, otherwise it will cause difficulty in

climbing.

c) Do not change the set pressure at will, otherwise it will affect the normal operation of the equipment.

4-18

4.1.8.3 Lifting pressure adjusting

Adjusting steps:

a) Remove the operating handle from the platform and open the hydraulic tray, and connect the

operating handle to the lower control line.

b) Connect a pressure gauge with a measuring range of 0 to 5000 psi/0 to 350 bar to the pressure

measuring connector.

c) Loosen the relief valve lock nut.

d) Insert the key to open the lower control system.

e) Hold down the function switch, move the joystick forward or backward while observing the

reading on the pressure gauge, and record the pressure value.

When adjusting the pressure, insert an Allen wrench into the adjusting nut, and turn clockwise to

increase the pressure, and turn it counterclockwise to decrease the pressure.

g) After the pressure adjustment is completed, tighten the relief valve lock nut, remove the pressure

gauge, and connect the operating handle to the upper control system.

ForZS4555HD/ZS4045HD/ZS3246HD/ZS2632HD/ZS2032HD/ZS1930HD/ZS4555HD-Li/ZS4045HD-

Li/ZS3246HD-Li/ZS2632HD-Li/ZS2032HD-Li/ZS1930HD-Li, lifting reliefvalve is shown in Fig.4-17.

1.Pressure measuring joint

2. lifting relief valve

Fig 4-17 Lifting relief valve diagram

4-19

For ZS4555DC/ZS4045DC/ZS3246DC/ZS2632DC/ZS2032DC/ZS1930DC/ZS4555DC-Li/

ZS4045DC-Li/ZS3246DC-Li/ZS2632DC-Li/ZS2032DC-Li/ZS1930DC-Li, lifting relief valve

is shown Fig. 4-18.

1.Pressure measuring joint

2. lifting relief valve

Fig 4-18 Lifting relief valve diagram

For ZS1530DC/ZS1530DC-Li, lifting relief valve is shown in Fig.4-19.

1.Pressure measuring joint

2. lifting relief valve

Fig 4-19 Lifting relief valve diagram

a) The set pressure must not be higher than the specified pressure, otherwise the components will be

damaged and even personal safety will be endangered.

b) The setting pressure cannot be less than the specified pressure, otherwise it will cause difficulty in

climbing.

c) Do not change the set pressure at will, otherwise it will affect the normal operation of the equipment.

4-20

SECTION 5 COMMON FAULTS ANALYSIS

When the work platform is in use, it is necessary to inspect it in time and to repair it when necessary. The

purpose of maintenance is as follows:

a) Ensuring the reliability of operations.

b) Maintaining the efficiency of the work platform.

c) Prevent downtime.

d) Maintain the value of the work platform.

e) Reduced maintenance costs.

5.1 Hydraulic System Failure

Table 5-1 Fault list of hydraulic system

Fault

No.

Cause

Solution

phenomenon

1.Replace phase line of power line.

2.Close unloading valve.

1.Motor reversal.

3.Filter or replace hydraulic oil and

2.Unloading valve not closed.

thoroughly clean the inside of the

hydraulic system.

3.The hydraulic oil is not clean,

due to rubber debris or other

4.Replace with antifreeze hydraulic

Work Platform

sundries, which cause one-way

oil.

fails to elevate.

valve of the manual oil pump to

close incompletely.

5.Check the solenoid valve for

4.Hydraulic oil freezes.

Lifting. If no electricity, try to

troubles hoot.If there is electricity,

5.Solenoid valve for lifting not

it is the fault with solenoid valve

open.

itself, then replace the solenoid

valve for lifting. Lift solenoid valve

should be kept clean and lubricated.

5-1

Table 5-1 Fault list of hydraulic system

Fault

No.

Cause

Solution

phenomenon

1.Open manual unloading valves.

2.Repair the stuck position to remove

1.Manual pump unloading valve

the foreign matters in the slot.

not fully open.

3. Replace with N32 low pour point

2.The scissor structure gets

hydraulic oil.

stuck, or there are foreign

The platform does

4. Press the button for lowering to see

matters in the slot for roller.

not lower.

if the valve is with electricity. If no

3. Hydraulic oil freezes.

electricity, try to troubleshoot; If

4. Valve for lowering fails to

electricity is available, replace the

work.

valve with a new one. The valve for

lowering should be kept clean and

lubricated.Ć

1.Check the valve in group valve. If

the seal surface of one-way valve is

found to be dirty, clean the valve.Ć

1.One-way valve discharge.

2.Check if the valve for lowering has

electricity, if there is no electricity,

Work platform

2.The valve for lowering is not

try to troubleshoot; if there is

self-lowering

tightly closed.

electricity with valve, then replace

3.Oil tank leakage.

the valve for lowering. The slide

valve of the valve for lowering

must be kept clean and mobile.Ć

3.Replace cylinder sealing elements.

1.Loose coupling nuts.

1. Tighten the coupling nuts.

Oil leakage from

2.O-ring sealing failure.

2. Replace the O-ring sealing.

pipe and joint

3.Worn-out pipes.

3. Replace the old pipes.

1.Insufficient hydraulic oil, and

Slow lifting, or

1.Add enough hydraulic oil.

air suction.

vibration of

2.Repair the suction pipe.

hydraulic system

2.Air leakage of oil suction pipe.

5-2

Table 5-1 Fault list of hydraulic system

Fault

No.

Cause

Solution

phenomenon

1.High and low speed switching

1.Repair high and low speed switch

Speed control

valve fault.

valves.Ć

problem for

2.Switch fault high and low

2.Repair high and low speed switch of

travelling

speed control.

controller.Ć

(hydraulic driving)

3.Motor fault.

3.Repair traveling motors.Ć

1.Repair or replacement of manual

1.Fault of brake manual pump.

pump.Ć

Brake problem

2.Clogged brake lines.

2.Clean the pipelines.

(hydraulic driving)

3.Brake fault.

3.Repair of brakes.Ć

1.Repair or replacement of gear

pumps.Ć

1.Gear pump fault.

2.Inspect and adjust the pressure of

2.Safety valve fault.

the relief valve.Ć

Slow climbing

3.Motor fault.

(hydraulic driving)

3.Repair or replacement of hydraulic

4.Brake fault.

motors.Ć

5.Overloading.

4.Repair or replacement of

brakes.Ć5.Unloading.

1.Low viscosity of oil.

1.Replacement of hydraulic oil.

2.Low temperature of hydraulic

Hydraulic system

oil.

2.Hydraulic system preheating.

noise

3.The backflow pressure of oil

3.Change the hydraulic pipeline.

return pipe is too high.

1.Clogging of radiators or

1.Clean the radiator or pipeline.

pipeline.

2.Replacement of hydraulic oil.

High temperature

2.Wrong type of hydraulic oil.

of hydraulic oil

3.Replacement of hydraulic oil.

3.Deterioration of hydraulic oil.

4.Refuel to the oil level.

4.Insufficient oil in the tank.

5-3

Table 5-1 Fault list of hydraulic system

Fault

No.

Cause

Solution

phenomenon

1.Air in hydraulic systems.

1.Air exhaust.

2.Loose pipe clamps.

2.Adjust and fix the pipeline.

Severe vibration of

3.Clogging of overflow or relief

3.Clean the valves.Ć

hydraulic pipelines

valves.

4.Repair or replacement of pumps,

4.Fault of pump, motor, or valve.

motors or valves.Ć

Oil leakage at

1.Joint not tightened.

1. Fasten joint.

hydraulic pipe

2.Damage to sealing elements.

2. Replacement of sealing elements.

joints

1.The hose is inconsistent with

1. Use proper hose.

the service pressure.

Hose burst

2. Replace the hose.

2.Aging and scratches of hose.

3. Clean the hoses and joints.

3.Clogging at hose joints.

Test pump and motor outlet pressure,

if lower than standard pressure, then

Oil leakage of

Hydraulic oil leakage from

the system has leakage. Check the

hydraulic pump

hydraulic pump and motor.

leak point, replace sealing element,

and motor joint

and tighten the sealing according to

standard torque.Ć

Do not dissemble or adjust when components with Ć break down. Contact the manufacturer.

5-4

5.2 Electrical System Fault

Table 5-2 Electrical system fault list

Fault

No.

Cause

Solution

phenomenon

1.Plug and connection of the

1.Restore plug and connection.

angle sensor are loose.

Fault of angle

2.Re-fixing of angle sensor.

sensor

2.Shift of installation position.

3.Replacement of sensor.

3.Damaged sensor.

1.Plug and connection of the

1.Restore plug and connection.

Fault of pressure

pressure sensor are loose.

sensor

2.Replacement of sensor.

2.Damaged sensor.

1.Restore the connection.

1.Loose connection of left and

2.Re-fix the left and right pothole

right pothole limit switch.

limit switch.

Switch fault of

2.Shift of left and right pothole

3.Check the structure of the pothole

pothole

protection limit switch.

slab whether it is normal or not and

3. Pothole slab cannot unfold

check whether there are any foreign

properly.

matters under the pothole slab

blocking the opening of the slab.

1.Check and restore upper limit

1.Loose connection of upper

switch connection.

limit switch.

2.Recalibration and re-fixing

The work platform

2.The position of upper limit

installation position of upper limit

is elevated to the

switch is shifted and cannot

switch.

highest position

be triggered properly.

and cannot be

3.Recalibration and re-fixing

3.Shift of upper limit switch

limited

installation position of upper limit

trigger metal plate position.

switch trigger metal plate.

4.Upper limit switch fault.

4.Replace upper limit switch.

1.Check and restore the lower limit

1.Lower limit switch connection

switch connection.

is loose.

2.Recalibration and re-fixing the

2.The lower limit switch

lower limit switch installation

Safe height limit

position is shifted and cannot

position.

anomaly or

be triggered properly.

position shifting

3.Recalibration and re-fixing trigger

3.Lower limit switch trigger

the installation position metal plate

metal plate is shifted.

of the lower limit switch.

4.Fault of lower limit switch.

4.Replace the lower limit switch.

5-5

Table 5-2 Electrical Vystem fault list

Fault

No.

Cause

Solution

phenomenon

1.Fault of communication

1.Whether CAN_H1 and CAN_L2 line

lines between platform

on the platform and ground controller

controller and ground

are properly connected.

System

controller.

communication

2.Or replacement of the platform

error

2.Fault of work platform

controller.Ć

controller.

3.Or replacement of the ground

3.Fault of ground controller.

controller.Ć

1.300A main fuse burned

1.Replacement of the 300A main fuse.

down.

2.Press 10A circuit breaker to restore

2.10A breaker tripping.

connection.

UP and DOWN

3.Abnormal cable connection

control can’t start

3.Replace connection cable or plug-in of

between platform and

normally.

platform and ground controller.

ground controller.

4.Replacement of platform controller.Ć

4.Fault of platform controller.

5.Replacement of ground controller.Ć

5.Fault of ground controller.

Do not dissemble or adjust when components with Ć break down. Contact the manufacturer.

5-6

Zoomlion Scissor lift ZS4555HD, ZS4045HD, ZS3246HD, ZS2632HD, ZS2032HD, ZS1930HD, ZS1530DC. Service and Maintenance Manual - page 3