For simple checking of the brake booster operation, carry out the following tests.
Run the engine for one or two minutes, and then stop it. If the pedal depresses fully the first time but gradually becomes higher when depressed succeeding times, the booster is operating properly, if the pedal height remains unchanged, the booster is inoperative.
With the engine stopped, step on the brake pedal several times.
Then step on the brake pedal and start the engine. If the pedal moves downward slightly, the booster is in good condition. If there is no change, the booster is inoperative.
With the engine running, step on the brake pedal and then stop the engine.
Hold the pedal depressed for 30 seconds. If the pedal height does not change, the booster is in good condition, if the pedal rises, the booster is inoperative.
If the above three tests are okay, the booster performance can be determined as good.
Even if one of the above three tests is not okay, check the check valve, vacuum hose and booster for malfunction.
Turn ignition switch OFF.
Remove the battery and battery tray. (Refer to Engine Electrical group - Battery)
Disconnect the fuel filter connector (A, B).
Loosen the fuel filter mounting nuts (A) and pivot the fuel filter (B) down out of the way.
Remove the master cylinder. (Refer to Master cylinder.)
Disconnect the vacuum hose (A) from the brake booster.
Remove the snap pin (A) and clevis pin (B).
Remove the brake booster mounting nuts (A).
Tightening torque:
12.7 ~ 15.7 N.m (1.3 ~ 1.6 kgf.m, 9.4 ~ 11.6 lb-ft)
Disconnect the brake tubes (A) from the HECU by unlocking the nuts counterclockwise with a spanner.
Tightening torque:
ABS: 12.7 ~ 16.7 N.m (1.3 ~ 1.7 kgf.m, 9.4 ~ 12.3 lb-ft)
ESP: 18.6 ~ 22.6 N.m (1.9 ~ 2.3 kgf.m, 13.7 ~ 16.6 lb-ft)
Pivot the brake tubes (A) down out of the way.
Remove the brake booster (B).
Inspect the check valve in the vacuum hose.
Do not remove the check valve from the vacuum hose.
Check the boot for damage.
Installation is the reverse of removal.
Before installing the pin, apply the grease to the joint pin.
Use a new snap pin whenever installing.
After installing, bleed the brake system. (Refer to Brake system bleeding)
Adjust the brake pedal height and free play. (Refer to Brake pedal height and free play adjustment)
