Mitsubishi 3000GT Service Manual page 539

1 Clutch
booster
side
manifold side
CLUTCH
(4) With the engine running, step on the clutch 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 <AWD>
When checking the check valve, keep the check valve fit
in the vacuum hose.
1. Remove the vacuum hose.
2. Check the operation of the check valve by using a vacuum
BLEEDING
Whenever the clutch tube, the clutch hose, and/or the clutch
master cylinder have been removed, or if the clutch pedal
is spongy, bleed the system.