2004 ISUZU TF SERIES oil

BRAKE CONTROL SYSTEM 5A-29

Dump Valve Test
Purpose: The purpose of this test is to detect brake
pipe and valve line harness wire for wrong connections
and valve trouble.
This test will help you confirm the result of your repai
r
service including the removal/reinstallation of brake
pipe, valve line harness and valve.
Test conditions: The ignition key is in the “ON” position
with the four wheels lifted up. The brake pedal is
stepped on, released and stepped on again with the
parking brake released.
Test procedure:
1. Connect Tech 2 with the vehicle, and select
Actuator Test Function from the menus.
2. Select a Solenoid Valve Test Menu from the
Actuator Test Menus.

060L300002
3. Select Dump Valve from the Valve Select Meuns.
4. Step on the brake pedal.
5. Make sure that the Dump Valve “ON” aimed at by
Tech 2 and the wheel released position are the
same. If different, check brake pipe, valve line
harness wiring and H/UNIT. Repair is needed if
abnormality is found.
6. Conduct Step 2 through Step 5 above on all the
four wheels.

060L300002
CAUTION: When conducting this test, please
observe the following cautions.

1. Do not start the engine.
2. Lift up the vehicle at a level floor.





Secure a clearance from the floor surface
enough to allow the lifted tire to rotate.
3. Maintain the lift up.
4. Wipe the floor surface to remove water and oil
so that the surface may become unslippery.
5. Do not load the vehicle.





When lifting up the vehicle, be sure to
observe the lifting up points. Refer to
vehicle lifting points in 0A section.

ANTI-LOCK BRAKE SYSTEM 5B-17

A03R300003
Legend


1.
Bench Press Fitting

2.
Steel Plate (25-30 mm thickness)


3.
Axle Shaft

4.
Sensor Rotor

Inspection and Repair
Make all necessary adjustments, repairs or part
replacement.


Check damage or powdered iron sticking to the
sensor rotor.


Check play in the sensor rotor.


Check a broken tooth or indentation in the senso
r
rotor.
NOTE: If replacement is required remove the sensor
rotor from the axle shaft assembly with brake. (Refer to
the section Rear Axle).


Discard the used sensor rotor.

(Snapring, Oil seal and Bearing)

Installation
1. Install the sensor rotor and assemble it into the axle
shaft assembly with back plate. (Refer to the section
Rear Axle)

5B -18 ANTI-LOCK BRAKE SYSTEM

420R300005
Legend


1.
Axle Shaft

2.
Oil Seal

3.
Bolt


4.
Back Plate

5.
Sensor Rotor

6.
Double Taper Roller Bearing

2. Install the axle shaft assembly with brake in the rea
r
axle. (Refer to the section Rear Axle).

BRAKES 5C-23

RTW35CSH001301

4) Failure on front master cylinder.
In case of failure on front master cylinder the pressure on
the inlet port (C) drop to zero. The pressure from inlet por
t
(A) acts on the bypass piston (2) and move it by comprising
of bypass spring (3). It makes possible the communication
between the inlet port (A) to outlet port (B) through the
bypass system. The outlet pressure (B) reaches the inle
t
pressure (A) and the LSPV is bypassed.


Valve Maintenance
In the case to fluid lead or other a abnormalities, faulty valve
should be replaced.
Note:
The load sensing proportioning valve is not repairable and
must be replaced as a completed assembly.


LOAD SENSING PROPORTIONING
VALVE (LSPV) ADJUSTMENT
RTW35CSH000301

1. Fluid Pressure Measurement
1) Rear axle weight adjustment
With an axle eight meter, adjust the rear axle weight with
a person sitting in the driver’s seat and a weight loaded
in the rear body.
N (kg/lb)

MODEL Adjustment value
4

2 7845 (800/1764)
4
2 HIGH RIDE
4

4 9316 (950/2095)

RTW35CSH000101





2) Installation of a fluid pressure gauge
Remove the air bleeder of the left hand wheel front and
rear brakes. Bleed air out of the fluid pressure gauge
with the measurement hose of the fluid pressure gauge
installed.
Pressure Tester: Brake oil (Fluid pressure gauge)
5-8840-2190-0

5C-24 BRAKES

RTW35CSH000201
3) Rear wheel cylinder fluid pressure measurement
Step on the brake pedal until the fluid pressure of the
front wheel cylinder gets to 9.8Mpa (100kg/cm
2), and
check the rear wheel cylinder fluid pressure. (Read the
value of the front wheel cylinder fluid pressure 2
seconds after the measurement. When measuring the
L.S.V fluid pressure, keep the brake pedal pressed
down without stepping it down twice or releasing it.)
Rear Wheel Cylinder Fluid Pressure MPa (kg/cm
2)

2WD 6.77
0.83 (69.0
8.5)
2WD (With High Ride
Suspension), 4WD 6.77

0.83 (69.0

8.5)

RTW35CSH000401
2. Oil Pressure Adjustment
1) LSPV spring length adjustment
Loosen the adjust nut of the LSPV spring joint, and
adjust the length of the LSPV spring.
When the oil pressure is insufficient, turn the adjust nu
t
clockwise to extend the span “A”. When the oil pressure
is too high, turn the adjust nut counterclockwise to
reduce the span “A”.


2) After adjustment, tighten the lock nut securely.
Lock Nut Torque N
m (kg
m/lb in)
11-20 (1.1-2.0/95-174)

BRAKES 5C-25


Filling Master Cylinder Reservoir
CAUTION :
Use only specified brake fluid. Do not use any fluid which
contains a petroleum base. Do not use a container which
has been used for petroleum based fluids or a container
which is wet with water. Petroleum based fluid will cause
swelling and distortion of rubber parts in the hydraulic
brake system. Water mixed with brake fluid lowers the
fluid boiling point. Keep all fluid containers capped to
prevent contamination.
Always fill the master cylinder reservoir when the engine
is cold.
Never allow the brake fluid to come in contact with the
painted surfaces.
The master cylinder reservoir must be kept properly filled
to ensure adequate reserve and to prevent air and
moisture from entering the hydraulic system. However,
because of expansion due to heat absorbed from the
brakes and the engine, the reservoir must not be
overfilled. Thoroughly clean reservoir cap before removal
to avoid getting dirt into reservoir. Add fluid as required to
bring level to the “MAX” mark on the reservoir tank. Use
“DOT 3” Hydraulic Brake Fluid.

Leakage of Brake Fluid
With engine idling, set shift lever in the neutral position and
continue to depress brake pedal at a constant pedal
application force.
Should the pedal stroke become deeper gradually, leakage
from the hydraulic pressure system is possible.
Make sure by visual check that there is no leak.




BLEEDING OF THE BRAKE HYDRAULIC
CIRCUIT
If air enters the bake lines, it will cause poor brake action.
Therefore, bleeding should be performed if the brakes have
been used with the level of brake fluid in the reservoir
excessively low or if brake pipes have been disconnected in
the course of brake servicing.
Bleeding operation calls for co-operative action of 2 persons.

Set the parking brake firmly while bleeding.

Perform bleeding operation with ENGINE RUNNING, to
prevent damage to push rod seal.

Make sure exhaust is suitably ventilated.

Bleed the hydraulic system with the fluid reservoir filled to
the specified level.

Bleed the system starting with the rear wheel cylinde
r
farthest from the master cylinder.

5C-54 BRAKES
Important Operations
When disassembling, inspecting or reassembling the master
cylinder assembly, take care not to bring the parts into contact
with mineral oil or dust. Wash the piston cups only with brake
fluid. Do not use gasoline or other mineral-base cleaning
solvents.



6. Ring ; Snap
Remove the snap ring from the cylinder body with pushing in
the primary and secondary pistons.
7. Stop Pin
Remove the stop pin from the cylinder body with pushing in the
primary and secondary pistons.


8. Piston Assembly ; Primary and Spring
9. Piston Assembly ; Secondary and Spring
Don’t remove the spring from the piston.

5C-62 BRAKES
360r300003
5. Vacuum Hose
The check valve (2) is built-in to the vacuum hose.
When installing the vacuum hose make sure that the arrow on
the hose is facing the engine (1).
Note :

Do not apply oil to the vacuum hose.



Installation direction is very important. The booster will no
t
operate if the vacuum hose is installed in the wrong
direction.


4JA1-T/4JA1-TC/4JH1-TC LHD model (with 2nd Battery)


RTW45CLF000101