ON-VEHICLE SERVICE
BASIC BRAKE SYSTEM
35A-6
(1) 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 defective. Go to
step 2.
(2) 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
defective. Go to step 3.
(3) 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
defective.
2. If the above three tests are okay, the booster is
OK. If one of the above three tests is not okay, the
check valve, vacuum hose, or booster is
defective. Check the check valve (Refer to
P.35A-6
), vacuum hose for leaks, high volume
engine vacuum applied to booster. Repair or
replace as necessary. If these are OK, replace the
booster and repeat this test starting at Step 1.
CHECK VALVE OPERATION CHECK
M1351009000451
CAUTION
The check valve should not be removed from the
vacuum hose.
1. Remove the vacuum hose (Refer to
P.35A-14
).
CAUTION
If the check valve is defective, replace it as an
assembly unit together with the vacuum hose.
2. Check the operation of the check valve by using a
vacuum pump.
BLEEDING
M1351001400563
CAUTION
Use only brake fluid DOT 3 or DOT 4. Never mix
the specified brake fluid with other fluid as it will
influence the braking performance significantly.
MASTER CYLINDER BLEEDING
The master cylinder used has no check valve, so if
bleeding is carried out by the following procedure,
bleeding of air from the brake pipeline will become
easier (When brake fluid is not contained in the
master cylinder).
1. Fill the reservoir with brake fluid.
2. Keep the brake pedal depressed.
AC000871AE
When engine
is stopped
When engine
is started
AC000872
Good
No good
AE
Vacuum pump
connection
Accept/reject criteria
Connection at the brake
booster side (A)
A negative pressure
(vacuum) is created and
held.
Connection at the intake
manifold side (B)
A negative pressure
(vacuum) is not created.
AC000873AE
A
B
Valve
Spring
Intake manifold
side
(does not hold)
Booster side
(holds)