Vacuum Brake Booster: Testing and Inspection
BRAKE BOOSTER ASSEMBLYON-VEHICLE INSPECTION
1. OPERATION CHECK
a. Depress the brake pedal several times with the engine off and check that there is no change in the pedal reserve distance.
b. Depress the brake pedal and start the engine. If the pedal goes down slightly, operation is normal.
If not, replace the brake booster.
2. AIR TIGHTNESS CHECK
a. Start the engine and stop it after 1 or 2 minutes. Depress the brake pedal several times slowly.
If the pedal can be depressed to the floor the first time, but on the 2nd or 3rd time cannot be depressed as far, the booster is airtight.
If not, replace the brake booster.
b. Depress the brake pedal while the engine is running, and stop the engine with the pedal depressed. If there is no change in the pedal reserve travel after the pedal is held for 30 seconds, the booster is air tight.
If not, replace the brake booster.
3. INSPECT VACUUM CHECK VALVE
a. Check that there is ventilation from the booster to engine, and no ventilation from the engine to the booster.
b. If any fault is found, replace the vacuum check valve.