wheel GREAT WALL SAFE 2006 Manual PDF

BR-6
Operation test of vacuum booster
Remark: check the operation of vacuum booster with the
vacuum booster tester if workable.
1.Operation inspection
(a) Before starting the engine, tread down the brake pedal
several times, and check the pedal reservation distance to
ensure there is no change occurs.
(b) Tread down the brake pedal and start the engine. If the
treaded pedals continue to move downward, which means
the operation is normal.
1. Inspection on Air-tight
(a) Start the engine for 1-2 min and then turn it off. Then
tread down the brake pedal slowly for several times, if the
pedal move downward continuously in the first, but
return gradually in the second or third time, which means
the vacuum booster has a good air-tight.
(b) Tread down the brake pedal when the engine is working,
then stop the engine, but tread the pedal down. If the
reservation distance doesnít change within the 30 seconds,
which shows the air tight of vacuum booster is good.
Air-bleeding of braking system
Remark: air-bleeding is required if any operation for braking
system is conducted or the pipe line is doubted to have air.
1. Fill the oil cup with the brake liquid
Check the liquid level of oil cup after the air in each wheel
brake pump is exhausted. If necessary, add the brake liquid.
2. Connect the vinyl resin pipe with the vent screws.
Insert the other end of pipe into the container with half brake
liquid.
Remark: the air-bleeding shall begin from the longest pipe line
when the wheel-brake cylinder is exhausting the air.
3. Air exhaust of the pipe line in braking system
(a) Tread down brake pedal slowly several times.
(b) Loosen the vent screws until the brake liquid flows out
while letting the assistant tread down the pedal. Then
screw up the vent screws.
(c) Repeat this approach until there is no air in the liquid.
4. Repeat the approach for the wheel-brake cylinder.
normal
abnormal
the third time
the second time
the first time
Braking System
Inspection and Adjustment

BR-14
Brake pad change
Remark: Check the thickness of the friction material of brake
pad through the observation hole on caliper body after the
vehicle covers thirty thousand; if the thickness fails to fall
within the specified range, change is required. (If the brake is
used often, the thickness of friction materials of brake
pad is required to check whether it is within the specified
range after the vehicle covers more than ten thousand,
if not, change it.
1. Tear down the front wheel;
2. Check the thickness of friction material of brake pad:
Check the thickness of friction material of brake pad through
the observation hole on caliper body, if it fails to be within the
specified range, change it.
Min thickness: 2.0mm
3. Raise the wheel-brake cylinder:
(a) Tear down the short bolts of sliding sleeve;
(b) Uplift the wheel brake pump and hang it with rope to
protect the brake oil pipe.
Remark: Do not loosen the brake oil pipe and the bleeding plug.
4. Tear down the following parts:
(a) Two braking pads;
(b) Two silent pad clusters;
(c) Four braking pad lock plates.
Braking System
Front Brake (Dr)

BR-15
5. Brake disc measurement
(See page BR-17)
6. Measure the radial run-out of the brake disc;
(See BR-18)
7. Mount the lock plate of brake pad.
8. Mount the new brake pad.
(a) Mount the silent pad cluster on brake pads of both the
inner and outer sides;
Remark: Pollution of oil stain or coat is not allowed on the
work faces of brake pad or brake disc.
(b) Draw out a little brake liquid from the liquid container to
prevent the brake liquid overflowing from the liquid
container;
(c) Press in the piston with the hammer lever or similar tool.
9. Mount the wheel-brake cylinder;
Mount and screw up the hex bolts (the hex bolts shall be coated
with the thread locking sealing agents.
Fastening torque
(38-50)N
m
Remark: only one brake pad can be changed in one time so as
to prevent the piston of other wheel being shot out.
Braking System
Front Brake (Dr)

BR-16
10. Mount the front wheel;
Screw up the fixing nut of wheel.
Fastening torque
(135
150)N
m
Disassembly of Wheel-brake Cylinder
1. Take apart the brake pipeline.
(a) Tear down the brake pipeline. And block the outlet with
a clean cork.
(b) Tear down the brake oil pipe bracket from the wheel-
brake cylinder.
2. Tear down the wheel-brake cylinder from the caliper
bracket.
Tear down the two hex bolts and the wheel-brake cylinder.
3. Tear down the brake pad:
(a) Two brake pad;
(b) Two silent pad cluster;
(c) Four brake pad lock plate.
Pump Disassembly of Wheel brake
1. Take apart the following parts:
(a) Two sliding sleeve;
(b) Four sliding sleeve dust cover;
(c) Two sliding liner.
Braking System
Front Brake (Dr)

BR-17
2. Tear down the piston dust cover snapping ring and the
piston dust cover;
Tear down the piston dust cover snapping ring and the piston
dust cover with screwdriver.
3. Tear down the piston from the wheel-brake cylinder:
(a) Put a wooden plate between the piston and the caliper
body.
(b) Tear down the piston from wheel-brake cylinder with the
compressed air.
Warning: Do not put your finger in front of the piston when
using the compressed air.
4. Tear down the piston sealing ring from the caliper body.
Tear down the piston sealing ring with bent needle.
Notice: the tools used shall not be sharp so as not to
scrape the piston sealing ring.
Check the front brake parts
1. Measure the thickness of brake pad liner;
Standard thickness
10.0mm
Min thickness
2.0mm
If the thickness is less than the min thickness or is unevenly
worn; change the brake pad.
2. Measure thickness of brake disc
Standard thickness
25.0mm
Min thickness
23.0mm
If the brake disc is scraped, repair it, if the brake is serious
worn to the degree that its thickness is less than the min thickness,
brake disc requires to be changed Braking System
Front Brake (Dr)

BR-18
3. Measure the bouncing value of the brake disc face;
Remark: verify the bearing is aligned correctly before
measuring.
The bouncing value of max face: 0.11mm
4. Change the brake disc according to the requirements
(a) Tear down the calipers body from the steering knuckle.
(b) Tear down the hub and the brake disc (See Page SA-11).
(c) Mount the new brake disc and screw up the connecting
bolts according to the specified torque.
Fastening torque
(60
79)N.m
(d) Mount the hub and brake disc assembly (see page SA-12);
(e) Mount the caliper bracket on the steering knuckle and
screw up the bolts according to the specified torque.
Fastening torque
(85
105)N.m
Cylinder Assembly of Wheel-brake
1. Preparation
All parts shall be washed, dried and cleared away the alien
materials before the assembly. And coat moderate vacuum
silicon base grease on the work faces of sliding sleeve dust
cover, sliding sleeve and the sliding liner; and plaster the
moderate rubber lubricant on the work faces of piston, piston
dust cover and the rectangular sealing ring.
2. Encase the piston sealing ring and piston in the caliper body;
(a) Screw the vent screw in the vent hole of calipers.
Fastening torque
(8
13)N.m
(b) Coat moderate rubber lubricant on the work face rectan-
gular sealing ring and encase the caliper body in groove.
(c) Encase the piston in the caliper body.
3. Encase the piston dust cover and the dust cover
snapping ring in the wheel-brake cylinder.
Braking System
Front Brake (Dr)

BR-19
4. Mount the sliding liner, sliding sleeve dust cover and
sliding sleeve.
(a) Encase the sliding liner and sliding sleeve dust cover in
the wheel-brake cylinder.
(b) Ensure the sliding sleeve dust cover in the ring groove of
wheel-brake cylinder hard.
(c) Encase the sliding sleeve in the sliding sleeve dust cover.
(d) Ensure the sliding sleeve dust cover in the ring groove of
sliding sleeve.
Mount of Brake Calipers
1. Mount the brake pad;
2. Mount the wheel-brake cylinder:
(a) Mount the wheel-brake cylinder;
(b) Mount and tighten the two assembling bolts (the bolts
shall be coated with the thread locking sealing agent).
Fastening torque
(38
50)N.m
3. Connect the brake pipeline.
Connect the brake pipeline with the calipers.
Fastening torque
(21
2)N.m
4. Observe the height of brake liquid level and, if
necessary, add in the brake liquid and exhaust the air
in braking system.
Notice: prevent the brake liquid from spraying on the
brake disc when exhausting air.
5. Check to see whether there is leakage of brake liquid. Braking System
Front Brake (Dr)

BR-20
Front Brake
Element figure
spring gasket12
123
separation padssilent pad
brake padbrake caliper
brake pad snapping ring
guide pin lock spring
sealing ringguide pin
dust cover steel gripping hoop
piston dust cover piston brake disc
: fastening torqueN
M
Change of Brake pad
Remark: In case there is a continuous screaming from the front
wheel when braking the vehicle during driving, check the
alarm pad for friction limit for brake pad. If there is friction
trace on the alarm pad with the brake disc, change the brake pad
1. Disassemble the front wheel;
2. Check the thickness of friction material of brake pad.
Check the thickness of friction material of brake pad, if it fails
to be within the specified range, change the brake pad.
Min thickness
2.0mm SFBraking System
Front Brake(SF)

BR-21
3. Disassemble the following parts:
(a) Guide pin snapping spring;
(b) Two guide pins;
(c) Brake pad snapping ring
(d) Two brake pads;
(e) Two silent pads; and
(f) Two separation pads
4. Measure the thickness of brake disc.
(See BR-24)
5. Measure the radial swinging of the brake disc.
(see page BR-24)
6. Mount on the new brake pad;
(a) Draw out a little brake liquid from the liquid container.
(b) Press in the piston with the hammer lever and similar tool.
Remark: Only one brake pad of the same wheel can be changed
in one time so as to prevent the piston on the other face ejecting
out.
(c) Mount two silent pads and two separation pads on the
new brake pad.
Remark: coat the brake oil for disc on the inner silent
pads.
(d) Mount the brake pad with the worn limit alarm pad on the
inner side, while the other brake pad on the outer side.
Note: Pollution of oil stain or coat is not allowed on the
work faces of brake pad or brake disc.
7. Mount the brake pad snapping spring;
Brake pad snapping spring shall be mounted at the lower
position;
Braking System
Front Brake(SF)

BR-22
8. Mount the two guide pins;
9. Mount the guide pin snapping spring
Disassembly of Wheel brake Pump
1. Disassemble the front wheel;í
2. Disassemble the brake pipeline;
Tear down the brake pipeline with a container containing the
brake liquid.
3. Disassemble the wheel-brake cylinder.
Tear down the two hex bolts and the wheel-brake cylinder.
4. Disassemble the following parts:
(a) Guide pin snapping spring;
(b) Two guide pins;í
(c) Brake pad snapping spring;
(d) Two brake pads;
(e) Two silent pads and
(f) Two separation pads.
Braking System
Front Brake(SF)