2006 GREAT WALL SAFE change wheel

BR-4Braking System
Notice and Troubleshooting
Troubleshooting (continued)
Trouble Causes Inspection items
There are quack-
quack noises
without using the
brake.Alien materials such as stone is reeled inside the wheel shell
Nuts on hub is loose;
The brake pedal or vacuum booster pushrod is adjusted
improperly;
The wheel bearing is worn or damaged or lubricated
insufficiently;
(disc type brake)
The outer end edge of brake pad support plate or brake pad
is dog-eared;
The silent pad is poor in properties;
The sliding liner is worn;
The mounting bolt is loose
The piston returns incompletely
(drum type brake)
There is loose or redundant part.Clear away the alien materials
Tighten the nut to the specified torque; and
change it in case the bolt hole is enlarged;
Check and adjust
Check, lubricate or change
Check repair or change
Check and make change according to real
situation
Check and make change according to real
situation
Check and tighten according to the necessity.
Check, repair or change
Check, take out or repair.
There is continuous
screaming noise
without using brakeThe brake pedal or vacuum booster pushrod is adjusted
improperly
The vacuum booster, master cylinder or wheel-brake cylinder
returns incompletely.
(Disc type brake)
The piston is rusted or seized;
The brake pad in brake caliper locates improperly;
There is friction between the brake disc and brake caliper
shell;
The brake pad support plate is mounted improperly;
There is interference between the abrasion indicating lamp
of brake pad and the brake disc due to the brake pad
abrasion;
(Drum type brake)
The pressure spring of brake shoe is soft rigidity, damaged
or unsuitable;
There is crack on the brake bottom plate flange;
There is interference of brake bottom plate with the brake
drum after it is bending or warping.
The brake drum interferes with the brake bottom plate or
with brake shoe due to it is processed improperly;
Other brake parts

There is loose or redundant part in braking system;
The brake liner is polished due to it is adjusted over-tightly;
The wheel bearing is worn, damaged or lubricated
insufficiently.Check and adjust
Check, repair or change
Check and add the lubricant according to
the necessity;
Repair or change
Repair or change
Repair or change
Change
Change
Repair or change
Repair or change
Change the brake drum
Check, maintain and change according to
the necessity;
Check, maintain and change according to
the necessity;
Check, maintain and change according to
the necessity;

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-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-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)