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NOTE: The pressure gauge, connected at the ALB NOTE: If the rear axle load determined is between (8) If the pressure measured differs from the spec- ification, adjust the ALB controller (Fig. 16). (9) Loosen the brake pedal winch. adjusting nut (Fig. 16) To increase pressure - (11) After adjustment reinstall the brake pedal winch and recheck the pressures and readjust if (12) Tighten the lock adjusting nut. MASTER CYLINDER DIAGNOSIS AND TESTING - MASTER CYLIN- (1) Start engine and check booster vacuum hose connections. A hissing noise indicates vacuum leak. (2) Stop engine and shift transmission into Neu- tral. (3) Pump brake pedal until all vacuum reserve in booster is depleted. (4) Press and hold brake pedal under light foot pressure. The pedal should hold firm, if the pedal (5) Start engine and note pedal action. It should fall away slightly under light foot pressure then hold firm. If no pedal action is discernible, power booster, (6) If the POWER BOOSTER VACUUM TEST passes, rebuild booster vacuum reserve as follows: (7) Wait a minimum of 90 seconds and try brake action again. Booster should provide two or more vac- POWER BOOSTER VACUUM TEST (1) Connect vacuum gauge to booster check valve with short length of hose and T-fitting (Fig. 17). (2) Start and run engine at curb idle speed for one minute. (3) Observe the vacuum supply. If vacuum supply is not adequate, repair vacuum supply. (4) Clamp hose shut between vacuum source and check valve. (5) Stop engine and observe vacuum gauge. millibars) within 15 seconds, booster diaphragm or POWER BOOSTER CHECK VALVE TEST (1) Disconnect vacuum hose from check valve. booster. Fig. 16 ALB CONTROLLER ADJUSTER NUT 1 - ALB ADJUSTER NUT Fig. 17 Typical Booster Vacuum Test Connections 1 - TEE FITTING VA BRAKES - BASE 5 - 17 |