1997 ISUZU TFS SERIES ECU

4C1-20 FRONT WHEEL DRIVE
Important Operations
10.Bolt
Bolt Torque N
m (kgfm/lbft)
82.4
7.8 (8.4 0.8/60.8 5.8)
13.Bellows
(1) Apply a thin coat of grease to the shaft for smooth
installation.
(2) Apply specified grease to the ½ space of the bellows.
14.Band
Note the setting direction.
After installation, check that the bellows is free from distortion.
15.Ball Guide
16.Ball Retainer
Install the ball guide with the smaller diameter side ahead onto
the shaft.
17.Snap Ring
Install the snap ring securing the ball retainer to the shaft.

5-16 BRAKES
From
primary
master cylinder From
Secondary
master cylinder
Operation
1) Outline
W hen the L.S.P.V.(Load Sensing Proportioning Valve)
detects a change in load weight, the load sensing spring
deflects.
Its reaction force is transmitted to the bottom of the load
sensing valve to secure an optimum rear wheel cylinder
fluid pressure break point in proportion to the actual load
weight.
Besides, if the front brake system should fail, the device is
designed to prevent the master cylinder fluid pressure from
decreasing and to apply it directly to the rear wheel cylinder
to obtain a sufficient braking performance.
Primary master
cylinder fluid
pressure Secondary master
cylinder fluid
pressure
2) Operation
(1) When the fluid pressure is under the break point.
The fluid pressure of the rear master cylinder passes
through a clearance between the valve seal and the piston
and acts on the rear wheel cylinder.
At this moment, a downward force is applied to the piston.
However, the compression spring force and reaction force
of the load sensing spring keep the piston in the upper
position by pushing upwards. (See the left figure.)
Primary master
cylinder fluid
pressure Secondary master
cylinder fluid
pressure
(2) When the fluid pressure is equal to the break point.
As the rear wheel cylinder pressure increases, it surpasses
the compression spring force and reaction force of the load
sensing spring, causing the piston to move downwards, so
that the piston butts against the valve seal to shut off the
fluid line between the master cylinder and rear wheel
cylinder. (See the left figure.)
(3) When the fluid pressure is over the break point.
W hen the fluid pressure increases further, the piston moves
upwards.
The moment the piston comes apart from the valve seal,
fluid pressure is applied to the rear wheel cylinder and the
piston moves downwards so that the fluid line is shut off
again.
This process goes on repeatedly to control the fluid
pressure to the rear wheel cylinder.

BRAKES 5-17
Secondary master
cylinder fluid
pressure
(4) When the front brake system fails.
W hen there is a failure in the front brake system, the fluid
pressure from the front master cylinder decreases.
As a result, the balance between the front and rear brake
side fluid pressures are lost at the control valve sleeve so
that the control valve sleeve moves upwards.
The control valve sleeve strikes against the piston, thereby
pushing the piston upwards.
Accordingly, the fluid pressure of the rear mater cylinder is
not decreased and is applied directly to the rear wheel
cylinder to secure a sufficient braking performance of the
rear brakes. (See the left figure.)
Valve Maintenance
In the case of 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.
ADJUSTMENT PROCEDURE OF LSPV
This adjustment should be performed with the battery voltage
applied to the valve.
1. Adjust the rear axle weight by loading the rear body as
necessary.
Rear axle weight kg (lbs)
TFR 750(1.654)
TFS 900(1.985)
Note:
The rear axle weight should be adjusted to the specified
value with a man seated in the driver seat.

5-22 BRAKES
1. Fill the brake fluid reservoir with brake fluid.
Handle the brake with reasonable care to avoid spillage as it
is damaging to paint.
Note:
Take care to prevent foreign matter from entry, when
replenishing or replacing brake fluid.
When pouring brake fluid, if diaphragm in the oil tank cap
is stretched, be sure to place it into original position,
(fasten it), and then cap it.
2. Connect a vinyl pipe to the bleeder screw on the wheel
cylinder, caliper bode or LSPV and the other end of the pipe
in a transparent container.
3. Pump the brake pedal several times and hold it depressed.
Loosen the bleed screw to release brake fluid together with
air bubbles.
Tighten the bleeder screw before pressure is released
completely.
4. Repeat the step in paragraph 3 above until the air bubbles
disappear completely.
Securely tighten the bleeder screw when the air bubbles
disappear completely.
5. Repeat the step in paragraph 4 above on the remaining
wheel cylinders.
Bleed the system starting with rear side farthest from the
brake fluid reservoir.
6. Fill the brake fluid reservoir to the specified level.
Pour brake fluid carefully so as not to produce air bubbles.
7. If the cap diaphragm is stretched, fasten the diaphragm and
the sure to cap it after it is placed to the original position.
Note:
Never reuse the old brake fluid.

CAB 10-5
Important Operation - Removal
6. Windshield Glass
Remove the windshield glass, carefully following the steps
listed below :
1) Use a knife to cut through part of the adhesive caulking
material.
2) Secure one end of a piece of steel piano wire (0.02 inches
in diameter) to a piece of wood that can serve as a handle.
3) Use a pair of needle nose pliers to insert the other end of
the piano wire through the adhesive caulking material at the
edge of the windshield glass.
4) Secure the other end of the piano wire to another piece of
wood.
5) W ith the aid of an assistant, carefully move the piano wire
with a sawing motion to cut through the adhesive caulking
material around the entire circumferance of the windshield
glass.
6) Lift the windshield from the body.
7) Clean any remaining adhesive caulking material from the
area of the body which holds the windshield.
8) Use a soft rag and unleaded gasoline to wipe off any
adhesive remaining on the windshield glass.
Important Operations - Installation
7. Engine Hood Rear Seal
Install the engine hood rear seal as shown in the illustration.
1 : Seal
2 : Clip
3 : Rear (windshield glass side)
4 : Front
6. Windshield Glass
1) Clean the windshield glass bonding surface.
2) Use a soft rag and unleaded gasoline to wipe off any
adhesive remaining on the body.
3) Mount the body window glass as shown in the illustration.
Attach spacers at seven (7) locations.

CAB 10-5
Important Operation - Removal
6. Windshield Glass
Remove the windshield glass, carefully following the steps
listed below :
1) Use a knife to cut through part of the adhesive caulking
material.
2) Secure one end of a piece of steel piano wire (0.02 inches
in diameter) to a piece of wood that can serve as a handle.
3) Use a pair of needle nose pliers to insert the other end of
the piano wire through the adhesive caulking material at the
edge of the windshield glass.
4) Secure the other end of the piano wire to another piece of
wood.
5) W ith the aid of an assistant, carefully move the piano wire
with a sawing motion to cut through the adhesive caulking
material around the entire circumferance of the windshield
glass.
6) Lift the windshield from the body.
7) Clean any remaining adhesive caulking material from the
area of the body which holds the windshield.
8) Use a soft rag and unleaded gasoline to wipe off any
adhesive remaining on the windshield glass.
Important Operations - Installation
7. Engine Hood Rear Seal
Install the engine hood rear seal as shown in the illustration.
1 : Seal
2 : Clip
3 : Rear (windshield glass side)
4 : Front
6. Windshield Glass
1) Clean the windshield glass bonding surface.
2) Use a soft rag and unleaded gasoline to wipe off any
adhesive remaining on the body.
3) Mount the body window glass as shown in the illustration.
Attach spacers at seven (7) locations.