Brake Booster Operating Test - Mitsubishi Electric Lancer Evolution-VII Workshop Manual

35A-8
C
Good
When engine is
stopped
Good
BASIC BRAKE SYSTEM -
2. If the brake pedal play is not within the standard value,
CLEARANCE BETWEEN BRAKE PEDAL AND FLOOR
BOARD
1. Turn up the carpet etc. under the brake pedal.
2. Start the engine, depress the brake pedal with
3. If the clearance is outside the standard value, check for
4. Return the carpet, etc.

BRAKE BOOSTER OPERATING TEST

No good
For simple checking of the brake booster operation, carry
out the following tests:
1. Run the engine for one or two minutes, and then stop
2. With the engine stopped, step on the brake pedal several
When engine is
started
3. With the engine running, step on the brake pedal and
No good
If the above three tests are okay, the booster performance
can be determined as good.
If one of the above three tests is not okay at least, the check
valve, vacuum hose, or booster will be defective.
On-vehicle Service
check the following, and adjust or replace if necessary:
Excessive play between the brake pedal and the clevis
D
pin, or between the clevis pin and the brake booster
operating rod
Brake pedal height
D
Installation position of the stop lamp switch, etc.
D
approximately 500 N of force, and measure the clearance
between the brake pedal and the floorboard.
Standard value (C): 90 mm or more
air trapped in the brake line and thickness of the disc
brake pad and dragging in the parking brake.
Adjust and replace defective parts as required.
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 defective.
times.
Then start the engine while the brake pedal is stepped
on.
If the pedal moves downward slightly, the booster is in
good condition. If there is no change, the booster is
defective.
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 defective.