GREAT WALL FLORID 2008 Service Manual

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Brake System
Brake System Components Arrangement Schematics.......95
Brake System Maintenance................................................96
Brake Pedal ........................................................................\
98
Parking Brake Control Mechanism Assembly...................102
Vacuum Booster with Brake Cylinder Assembly ...............103
Anti-lock Brake System ....................................................107
ABS General Problem Maintenance and
Areas of Importance .........................................................109
Steering Knuckle and Hub Brake Assembly .....................112
Front Brake Caliper ..........................................................118
Rear Brake .......................................................................124
Rear Support Axle ............................................................131

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Brake System Components Arrangement Schematics
Brake pedal assembly
Vacuum booster with brake cylinder assembly
Left steering knuckle and hub brake assembly
Left parking brake cable assembly
Rear brake assembly RHRear brake drum
Rear wheel speed sensor assembly RH
Right parking brake cable assembly
ABS controller assembly
Right steering knuckle and hub brake assembly
Brake line assembly
Rear wheel speed
sensor assembly LH
Front wheel speed sensor assembly RHFront wheel speed sensor assembly LH
Rear brake assembly LH
Parking brake control mechanism assembly

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Brake System Maintenance
Brake fluid inspection and replacement
Brake fluid directly influences the brake performance and the operating conditions and use life of the brake
system components. Brake fluid has very strong hygroscopic properties, and thus absorbs water easily,
which will then deteriorate the metal and rubber pieces. Polluted and deteriorated brake fluid or its mixture
would cause the brake fluid to boil and gasify, hence reduces braking efficiency. Therefore, pay attention to
the items below when filling or changing the brake fluid:
1. Containers used to hold brake fluid must be tightly closed and sealed
2. Brake fluid is poisonous and damaging to the paint. Hence if it gets on the vehicle surface, rub it
off at once
3. If water or other contaminates found in the brake fluid, and the brake master cylinder's piston seal
has been broken, then the brake fluid and all the rubber pieces inside the brake system including
the brake hose must be replaced
4. The correct brake fluid level in the reservoir must be between MAX and MIN. After the vehicle has
been driven for over 1000 km, check the brake fluid level in the reservoir. If the brake fluid level is
not up to regulation, more brake fluid should be added to the reservoir \
until it reaches MAX.
Hydraulic component inspection and system flushing
1. If the oil-based solvent gets into the hydraulic system, flush the whole system and change all of
the rubber pieces
2. Clean your hands before installing new rubber pieces or other components
3. Do not use regular solvents (kerosene, gas, etc.) when inspecting or cleaning hydraulic
components, instead use absorbing alcohol or brake fluid
4. After inspecting the components, drain the brake fluid from the system. Use new brake fluid to
flush the system. Afterwards, add new brake fluid to perform hydraulic system exhaust
5. Flushing completion sign: When the brake fluid flowing out of the dump valve is clear from any
contaminate.
Hydraulic pressure system drainage
If the brake fluid inside the whole hydraulic pressure system needs to be emptied, open all the bleed screws
with each connected to a hose, as to allow the brake fluid to flow into a container. Step on the pedal slowly
until only air flows out. During the whole procedure, make sure all the \
valves are open.
Hydraulic pressure system air bleeding
The hydraulic brake system must work under a vacuum environment. The air will cause spongy brake or
overall brake failure when it flows into the hydraulic system. It is extremely necessary to bleed system air
when performing any operation on the brake system or if any air inside t\
he brake system is suspected.
1. Air bleeding sequence
If air inside the brake master cylinder is suspected, first perform air bleeding.
(a) If numerous valves are equipped, air bleed each valve
(b) Another sequence principle is: Air bleed from the wheel brake furthest away from the master cylinder.
The air bleeding sequence for the LHD modules is: rear right wheel - left rear wheel - front right wheel
- front left wheel, Right rudder vehicles: rear right wheel - left rear wheel - front left wheel - front right
wheel.
2. Air bleeding method
(1) Manual air bleeding
Use the brake pedal or pump as the air bleeding power source. When the air bleed screws are open, vent the
brake fluid containing the bubbles from the system. Usually this is simultaneously done by two people. One
steps on the brake pedal and the other operates the air bleed screws. Important points to take note of when
performing the operation:
(a) Place the ignition switch to the off position and step on the pedal repeatedly to remove the
vacuum pressure or hydraulic pressure.
(b) Before and after air bleeding, add clean brake fluid into the master cylinder until it reaches
the correct (stated) level.
(c) Check the fluid level frequently to make sure that more than half of the reservoir's capacity is
available.
(d) Bleed screws should only be opened when the pedal is pressed down, and closed before the
pedal is loosened. Meanwhile, check if the vented brake fluid has bubble\
s inside.

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(e) Make sure not to let the system valves block the air bleeding.
(f) When the brake fluid that flows out of the hose or connector has no bubbles, it means that the air
in the system has been exhausted. There is still air inside the system if the hose inserted into the
brake fluid is still bubbling when pressing down the pedal.
(g) Keep the free end of the hose immerged in the brake fluid to avoid air from flowing into the
system while opening the screw.
(h) While air bleeding, hammer the casting part of the vibrating brake device with a rubber hammer.
This is helpful for removing bubbles deep in the brake fluid.
(i) If air in the master cylinder is suspected, then perform air bleeding on the master cylinder first,
then the wheel cylinder or brake caliper.
(j) When releasing air from the tires, generally make sure to release air out of all the tires.
(k) To avoid the possibility of air reversely entering into the system, a bleeder hose that has a check
valve could be used.
(2) Pressure blow-off
Under the proper conditions, a pressure blow-off device can be used to release the air inside the brake system.
3. Air releasing sequence
(1) Master cylinder air bleeding
If the master cylinder does not have air bleed screws, perform the follo\
wing steps:
(a) Check the brake fluid level inside the master cylinder’s reservoir and add to it if necessary.
(b) Slowly take off the front brake pipe connector until the brake fluid flows out from the end.
(c) Reconnect the brake pipe, but do not tighten it.
(d) Slowly step down and press on the brake pedal, check if the brake fluid flowing out of the connector
contains bubbles.
(e) Tighten the pipe fitting.
(f) Have the assistant loosen the pedal, wait for 15 s.
(g) Repeat the above steps until all the air is released.
(h) Take off the rear brake pipe connector, repeat the above steps.
(2) Wheel brake air releasing
(a) Check the brake fluid level inside the master cylinder’s reservoir and add to it if necessary. During the
entire air releasing period, check repeatedly and add promptly.
(b) Connect one end of the bleeder hose with the bleed screw and the other end immerged in the brake fluid.
(c) Have the assistant step on the pedal several times, raise the pedal gradually until it cannot be stepped on
any more, then forcibly press on the pedal once more.
(d) Loosen the bleed screw, check if there are any bubbles in the brake fluid flowing out. Meanwhile, slowly
lower the pedal.
(e) When the brake pedal is close to the stroke end or the out flowing brake fluid does not have any bubbles,
tighten the bleed screw.
(f) Have the assistant release the pedal and wait for 15 s.
(g) Repeat the above steps until there are no bubbles in the flowing brake fluid when the screw is loosened.
(h) Release the air for all the wheels in turn using the same method.
(i) After releasing the air from the entire system, switch the ignition to the on position.
(j) Inspect the stroke of the brake pedal and its reaction.
(k) Inspect the lighting condition of the brake warning lamp, and repeatedly perform maintenance or air
bleeding if necessary.
( l ) Add brake fluid to the reservoir until the specified fluid level, air bleeding is complete.

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Brake Pedal
Components
Areas of Importance
1. During removal, all components should be gently handled to avoid knocking, especially the junction
surface. All components should be placed in order to avoid losing or taking the w\
rong parts.
2. Keep all parts clean and free of dust, scuffs, rust, corrosion, oil build-up, or any other contaminants.
3. All rubbing surfaces in a relative motion must be coated with lubricant\
.
4. During installation, strictly adhere to the standard torque for installi\
ng nuts.
5. While installing the return spring, be careful to avoid operator injury \
from it bouncing back.
Troubleshooting
SymptomsPossible causesEliminating methods
Brake pedal cannot return
to the original position
Return spring is brokenReplace the spring
Return spring's fixed end comes offCheck, secure in place
Feels slippery when
stepping on the pedal
Pedal pad is worn outReplace
Pedal pad comes offReinstall
Stepping on the pedal
produces abnormal noise
The plastic bushing is seriously worn outReplace
Spring brokenReplace
Spring's fixed end comes offCheck, re-fix
Pedal pad
Cotter pin
Return spring
Pedal shaft
Brake pedal bracket
welding assembly
Brake pedal lever welding assembly
Bushing
Nut
Limiting stopper
Center pin

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Disassembly of the brake pedal assembly
1. Remove the lock nut with an outer hexagonal wrench.
2. Remove the pedal shaft.
Caution: Please do not place the pedal shaft directly
on the ground, as to guarantee its cleanness.
3. Remove the brake pedal assembly.
Caution: Set it down gently to avoid damaging its
surface finish.
4. Remove the pedal pad, bushing, and limiting stopper
from the pedal lever assembly.
Caution: Ensure cleanliness of the entire set's surface.
Installation of the brake pedal assembly
1. Apply lubricant on the inside of the axle tube-brake
pedal and the outside of the bushing, then install the
bushing into the axle tube-brake pedal.
Lock nut
Pedal shaft
Pedal lever assembly
Pedal pad
Axle tube
Bushing

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2. Install the pedal pad and limiting stopper to the pedal
lever.
3. Apply lubricant on the inner bushing and the outer
pedal shaft. Install the pedal lever assembly, pedal
shaft, and brake pedal bracket welding assembly.
4. Put on a nut, and tighten the nut and spring washer
using a 30 N·m torque.
Brake pedal examination and adjustment
1. Check if the pedal height is correct.
Height between pedal and the lower cowl panel: 109 mm
Pedal push rod's working empty stroke: 2 mm
2. Adjust pedal height if necessary.
(a) Disconnect the brake lamp's switch wire connector,
loosen the lock nuts, rotate the brake switch and
unscrew it until no contact with the brake pedal's
limiting stopper.
(b) Loosen the control rod lock nut and use combination
pliers to rotate the control rod and adjust the brake
pedal height to its standard value. After arriving at the
standard value, tighten the lock nut, and make sure the
working empty stroke of the pedal push rod is 2 mm.
(c) Rotate the brake lamp's switch and push it in until it
barely contacts with the brake pedal limiting stopper,
continue rotating 1/2-1 circle, then tighten the lock nut.
(d) Connect the brake lamp's switch wire connector.
(e) When the brake pedal is loose, the brake lamp should
be off.
Pedal height
Pedal padLimiting stopper

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3. Inspect the pedal free play.
When the engine is off, step on the brake pedal two to three
times, after the brake booster's influence is removed, push
the brake pedal by hand until resistance is felt, then measure
its movement (free play). Should satisfy standard value
regulation.
Pedal free play: 6-9 mm
4. Adjust pedal free play if necessary.
(a) If the stroke value is incorrect, rotate the pedal push
rod to adjust the free play.
(b) Start the engine to confirm the pedal free play.
(c) After adjusting the pedal free play, check the pedal
height.
(d) The relative height gap between the brake pedal and
the clutch pedal is 0-8 mm.
(e) The relative height gap between the brake pedal and
the accelerator pedal is 45±5 mm.
5. When the clearance between the brake pedal shaft
and the bushing is too big, one should remove and re-
place the pedal.
6. As shown, check if the pedal's remaining distance is
correct.
Pedal free play
Pedal’s remaining distance

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Parking Brake Control Mechanism Assembly
Components
Parking brake lever removal and installation
1. Removal
(a) Remove the auxiliary facia console, and pull the park-
ing brake lever to the lowest position.
(b) Remove the two hexagon head bolts used to stablize
the parking brake lever onto the vehicle floor.
(c) Loosen the parking brake cable's adjusting nuts with a
wrench, and take the cable out from the equalizing frame.
2. Installation
Complete the parking brake control mechanism's installation
by reversing its removal sequence. Please pay attention to
the items below:
(a) The open end of the parking brake lever assembly's
cable clamp should face down.
(b) While installing the parking brake lever, the assembly
structure must be properly adjusted, which is usually 5
to 8 gears.
(c) The tightening torque of the coupling bolt for the
parking brake control mechanism assembly and vehicle
body is 20 N·m.
A
B
C
D
Q1420612
Q1460825
Q32006Q1420616
Parking brake control mechanism assembly
Q1420612
A
B
CD
Left parking brake cable assembly
Right parking brake cable assembly
Button
control lever Control jacket
Dust cover
Lock nutLock nut
Switch assembly
Adjusting nutEqualizing frame
Pull rod

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Vacuum Booster with Brake Cylinder Assembly
Components
Areas of Importance
1. The vacuum booster with brake cylinder assembly is tightly connected with the brake pedal assembly on
the cowl panel using four nuts. It is also connected with the brake pedal push rod via an center pin and
lock pin. Thus before removal of the assembly, first loosen the rigid pipe fitting with an open-end wrench,
disconnect the lock pin and center pin using pliers, loosen the four nuts, and then proceed with the booster.
2. Tighten the lock nuts on brake master cylinder and vacuum booster according to the specified torque,
and coat with signal paint.
3. Dimensions between the rear housing head face and the adjusting fork hole center is adjusted to
standard before it leaves factory. Please do not adjust it again.
4. The vacuum booster valve rod on the vehicle must be in a free state.
5. The brake master cylinder's working agent is DOT4 brake fluid. It must not be mixed with any other
brake fluid.
Problems and symptomsCausesEliminating methods
M a s t e r c y l i n d e r ' s o i l r e s e r v o i r i s severely leakingThe master cylinder, slave cylinder, or hydraulic line is leaking.Eliminate the areas with leaks (in general, it may be that the pipe fitting's tightening torque is not enough, check one by one and tighten as necessary)
1. Vacuum booster not sufficient2. No boost when the engine is off3. May lead to unsteady engine idling when severe
1. Under non-operating conditions, the vacuum booster leaks air.2. Front and rear housing connection are not sealed.3. Booster's front and rear gas seal sealing failure.4. Vacuum check valve leaks.
1. Replace the front and back gas seal and control valve assembly.2. Replace the vacuum booster.3. Replace the vacuum check valve assembly.
Brake pedal is heavy with no boost effect1. Under non-operating conditions, the vacuum booster leaks air.2. Booster diaphragm worn and damaged.3. Control valve ring cup worn and damaged.
1. Replace the front, back gas seal and booster diaphragm.2. Replace the vacuum booster.3. Replace the control valve assembly.
Spongy pedal when braking1. There is air in the brake fluid.2. Cylinder or slave cylinder leaks oil.3. There is brake line seepage.
1. Eliminate the air in the system.2. Inspect the cylinder and sub-pump cup and replace with new parts.3. Inspect the pipeline and eliminate the seepage.
When continuously step on the brake pedal, the pedal will gradually change and expand till the highest extend.
Pump valve opening blockage.Brake fluid cleanliness is insufficient, please replace the brake fluid.
Troubleshooting
Oil cup cover
Oil cup body
Check valve
Check valve seat
Vacuum booster
Pad
Lock nut
Rod clevisCoupling nut
Rectangular sealing ringCylinder body
Fluid supply sealing ring