1991 MITSUBISHI 3000GT brake fluid

35-46SERVICE BRAKES - Service Adjustment Procedures
BRAKE FLUID LEVEL SENSOR CHECK
I
MBSFBAF
Good
k‘14UOO61
When engine is
stoppedNo good
When engine isstarted
14UOO6C)Checkvalve/1. Connect a circuit tester to the brake fluid level sensor.
I
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&Jno continuity when the float surface is above “A”, and if,there is continuity when the float surface is below “A”.
BRAKE BOOSTER OPERATING INSPECTION
M35FCAOFor simple checking of brake booster operation, carry out the
following tests.
1.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 CHECKM35FNALWhen 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.1
d~
TSB Revision

SERVICE BRAKES - Service Adjustment Procedures35-47Valve
Spring
Pressure
w-wPressure
,*’ISplit point
,*“”,’,’,’I’
,’,’
output
br.,’
,’pressure
Input pressure14U005E
2.Check the operation of the check valve by using a vacuum
pump.Vacuum pump connection
Connection at the brake
booster side @
Connection at the intake
manifold side @created and held.
created.
Caution
If the check valve is defective, replace it as an assembly
unit together with the vacuum hose.
PROPORTIONING VALVE FUNCTION TESTMOBFKAK1. 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
pressure (split point).
Standard value: 3.75
- 4.25 MPa (533 -- 604 psi)
(2) Output fluid pressure when input fluid pressure is 8.0MPa (1,138 psi)
Standard value: 5.23
- 5.73 MPa (744 - 815 psi)
(3)
C$txrt pressure difference between left and right brake
Limit: 0.4
MPa (57 psi)
4. If the measured pressures are not within the permissible
ranges, replace the proportioning valve.
TSB Revision

35-48SERVICE BRAKES - Service Adjustment Procedures
BLEEDINGCautionM35FYAOUse the specified brake fluid. Avoid using a mixture of the
specified brake fluid and other fluid.
Specified brake fluid: Conforming to DOT314POO3C
1
14A045
When new
When wornWear
indicator
Lrakedisc
indicatorBrake
disc
14FOO4CBLEEDING THE MASTER CYLINDER
If the master cylinder is empty of brake fluid, bleed the cylinder
as follows.
(1) Fill the reserve tank with brake fluid.
(2) Depress and hold the brake pedal.
(3) Let your fellow worker plug the master cylinder outlet with
finger.
(4) Keeping the condition (3), release the brake pedal.
(5) Repeat steps
(2) to (4) three to four times while filling the
master cylinder with brake fluid.
BLEEDING THE BRAKE PIPE LINE
Bleed the brake pipe line with the engine running in the order
shown in the illustration.
Caution
When adding brake fluid on vehicles with ABS, be sure to
fit the filter to the reserve tank.
FRONT DISC BRAKE PAD CHECK AND REPLACE-
MENTM35FQAG
NOTEThe brake pads have wear indicators that contact the brake disc
when the brake pad thickness becomes 2 mm
(.079 in.), and
emit a squealing sound to warn the driver.
&ionI

Brake tube flare nut15Nm
11 ft.lbs.
m14FO38

Post-installation Operationl Supplying Brake Fluid
l-----l
l Bleeding(Refer to P.35-48.)l Adjustment of Brake Pedal
(Refer to P.35-45.)

81
‘414ux216 1
Sealant: 3M ATDPart No.
-----I8663 or equivalent
SERVICE BRAKES - Master Cylinder and Brake Booster35-67
MASTER CYLINDER AND BRAKE BOOSTER
L
REMOVAL AND INSTALLATION
14 NmIO ft.lbs.
10 Nm
7 ft.lbs.
Master cylinder removal steps
*I)1. Low-pressure hose
2. Brake fluid level sensor connector
3: Brake tube connection
4. Master cylinder
l e .Adjustment of clearance between brake
booster push rod and primary piston
Brake booster removal steps
4.Master cylinder5.Vacuum hose6.Vacuum tubel a7. Vacuum hose with check valve8.Fitting9.Cotter pin10.Washer11.Clevis pin.
12.Sealer13.Spacer
14.Brake booster
lb14FOlll
9 10
bpr.
m
cl11
1 t
TSB Revision

SERVICE BRAKES - Master Cylinder and Brake Booster35-69light
scale14AO471
DISASSEMBLY AND REASSEMBLY
Brake fluid: Conforming to DOT3
Disassembly steps
1. Reservoir cap assembly
2. Diaphragm
3. Reservoir cap4. Filter
5. Brake fluid level sensor
6. Float7. Reservoir stopper bolt
8. Reservoir
9. Reservoir seal
*I)IO. Piston stopper bolt
11. Gasket
a*12. Piston stopper ring
13. Primary piston assembly
a*14. Secondary piston assembly
15. Master cylinder body(3) Measure the dimension
(D)der mounting surface on brake booster and the push
rod end.
NOTETo obtain
(D), first take measurement with a square
placed on the brake booster. Then, subtract the thick-
(D).
(3),push rod and primary piston.
Standard value: A (A
=- C - D)
7
+ 8 inch brake booster
0.55
- 0.75 mm (.022 - .030 in.)
8
+ 9 inch brake booster
0.65
- 0.85 mm (.026 - .033 in.)
(5) If the clearance is not within the standard value range,
adjust by changing the push rod length by turning the
adjustable end of the push rod.
Caution
Improper clearance may cause excessive brake
drag.M35HA-
-
14FOll3
Do not disassemble the primary ancH secondary
piston assembly.
1 TSB’ Revision

SERVICE BRAKES - Brake Line
BRAKE LINE
REMOVAL AND INSTALLATION35-71
M35uA. - ABS>
Pre-removal Operationl Draining of Brake Fluid
Post-installation Operationl Supplying Brake Fluid
l Bleeding (Refer to P.35-48.)
Flared brake line nuts
15 Nm
11 ft.lbs.1. Brake hose
2. Brake tube (strut)
3. Brake tube (A)
4. Brake tube
(B)5. Brake tube (front, R.H.)6. Brake tube (front, L.H.)7. Brake tube (main, R.H.)8. Brake tube (main, L.H.)14. Proportioning valve
Caution
Do not disassemble the proportioning valve because
its performance depends on the set load of the
spring.
TSB Revision

35-76SERVICE BRAKES - Front Disc BrakeLubrication points
!14KO6914Y184
-
ai
Brake fluid: Conforming to DOT3
Grease: Repair kit grease (orange)14A0541
Grease: Repair kit grease (orange)
14LO128
Grease: Repair kit grease (orange)TSB Revision
1

SERVICE BRAKES - Front Disc Brake35-77
14AO553
14AO55114uoo7i
SERVICE POINTS OF DISASSEMBLYM35LFCB
When disassembling the front disc brakes, disassemble both
sides (left and right) as a set.
7. REMOVAL OF PISTON BOOT
/ 8. PISTON
Send compressed air from the port to which brake hose is
installed and remove the pistons and piston boots.
Caution
Send the air gradually, and using the handle of a plastic
hammer etc., keep the protrusions of the two pistons
even.
If one of the two pistons is removed, the other one
cannot be removed.
9. REMOVAL OF PISTON SEAL
(1) Remove piston seal with finger tip.
Caution
Do not damage the cylinder inner surface.
(2) Clean piston surface and inher cylinder with trichloro-
ethylene, alcohol or specified brake fluid.
Specified brake fluid: Conforming to DOT3
INSPECTIONMOBLGCBl Check cylinder for wear, damage or rust.
l Check piston surface for wear, damage or rust.
l Check caliper body or sleeve for wear.
l Check pad for damage or adhesion of grease, check
backing metal for damage.
PAD WEAR CHECK
Measure thickness at the thinnest and worn area of the pad.
Replace pad assembly, when pad thickness is less than the limit
value.
Standard value: 10.0 mm (.39 in.)
Limit value: 2.0 mm
(08 in.)
Caution
1.Whenever the pad is to be replaced, replace the pads on
both right and left wheels as a set.
2. If there is a large difference in thickness between the
pads on the right and left wheels, check the sliding
portions of the caliper.
TSB Revision