Mitsubishi 1992 3000GT, Service Manual

Page: 891 / 1308

SERVICE BRAKES
On-vehicle Service
Valve
Spring
Pressure
Proportioning valve
Split point
output
pressure
Input pressure
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.
2. Check the operation of the check valve by using a vacuum
Vacuum pump connection Accept/reject criteria
Connection at the brake A negative pressure (vacuum) is
booster side (1) created and held.
I
Connection at the intake A negative pressure (vacuum) is not
manifold side (2) created.
Caution
If the check valve is defective, replace it as an assem-
bly unit together with the vacuum hose.
PROPORTIONING VALVE FUNCTION TEST
1. Connect two pressure gauges, one each to the input
side and output side of the proportioning valve, as shown.
2. Air bleed the brake line and the pressure gauge.
3. While gradually depressing the brake pedal, make the
following measurements and check to be sure that the
measured values are within the allowable range.
(1) Output pressure begins to drop relative to input pres-
sure (split point).
Standard value:
Convertible (704-775 psi)
Hatchback 3.75-4.25 (533-604 psi)
(2) Output fluid pressure when input fluid pressure is
10 (1,422 psi)
Standard value:
Convertible 6.72-7.52 psi)
Hatchback 5.82-6.62 (828-842 psi)
(3) Output pressure difference between left and right
brake lines
Limit: 0.4 (57 psi)
4. If the measured pressures are not within allowable ranges,
replace the proportioning valve.
TSB Revision