Mitsubishi 3000GT 1991 Service Manual page 768

SERVICE BRAKES
Good
No good
When engine is
When engine is
stopped started
Checkvalve
BRAKE FLUID LEVEL SENSOR CHECK
1. Connect a circuit tester to the brake fluid level sensor.
2. Move the float from top to bottom and check for continuity.
3. The brake fluid level sensor is in good condition if there is 'k&J
no continuity when the float surface is above "A", and if
there is continuity when the float surface is below "A".
BRAKE BOOSTER OPERATING INSPECTION
For simple checking of brake booster operation, carry out the
following tests.
Run the engine for one or two minutes, and then stop it.
2. Step on the brake pedal several times with normal
pressure.
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
faulty.
3. With the engine stopped, step on the brake pedal several
times with the same pressure to make sure that the pedal
height will not change.
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 faulty.
4. 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 faulty.
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 last, the check
valve, vacuum hose, or booster will be faulty.
CHECK VALVE OPERATION CHECK
When checking the check valve, keep the check valve fit in the
vacuum hose.
1. Remove the vacuum hose.
Caution
The check valve is press-fit inside the vacuum hose and
do not remove the check valve from the vacuum hose.
TSB Revision
,