Accord L4-1955cc 2.0L SOHC 2-bbl (1986)
Vacuum Brake Booster: Testing and Inspection
FUNCTIONAL TEST
1. With the engine stopped, depress the brake pedal several times, then depress the pedal hard and hold that pressure for 15 seconds. If the pedal
sinks, the master cylinder, brake line or a wheel cylinder is faulty.
2. Start the engine with the pedal depressed. If the pedal sinks slightly, the vacuum booster is working. If the pedal height does not vary, the booster
or check valve is faulty.
LEAK TEST
1. Depress the brake pedal with the engine running, then stop the engine. If the pedal height does not vary while depressed for 30 seconds, the
vacuum booster is OK. If the pedal rises, the booster is faulty.
2. With the engine stopped, depress the brake pedal several times using normal pressure. When the pedal is first depressed, it should be low. On
consecutive applications, pedal height should gradually rise. If the pedal position does not vary, check the booster check valve.
