air bleeding GREAT WALL FLORID 2008 Service Manual

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Clutch Master Cylinder Installation
Installation of clutch system is reverse to its removal, but
since the whole clutch system uses hydraulic assistance,
make sure to air bleed it after the installation is completed.
Detailed steps as follows:
(a) Plug one end of the long transparent connection hose
(about 0.5 m long) into the bottom of bleed screw, and
the other end into a fixed container.
(b) Loosen the bleed screw via the open end of the M8,
meanwhile ask the assistant to step on the clutch pedal
repeatedly until no air bubbles can be seen in the hose.
R e m a r k : R e s i d u a l a i r i n t h e c l u t c h s y s t e m h a s b e e n
completely exhausted.
(c) Lastly, lock the bleed screw.
Caution: Refilling the brake fluid reservoir should be
performed while air bleeding the clutch.
Clutch Pedal Removal
1. Remove the battery's negative cable.
2. Remove the glove box at the left of the dashboard.
3. Remove the cotter pin at the U-joint of the clutch
master cylinder, and separate the center pin and the
pedal lever.
4. Remove the clutch pedal bracket from the cowl.
5. Remove the clutch pedal.
(a) Move the clutch pedal to the maximum stroke position.
(b) Take down the return spring.
(c) Remove the bolts and nuts.
(d) Take the pedal lever down from the pedal bracket.
Clutch Pedal Installation
1. Install the clutch pedal.
(a) Install the return spring.
(b) Install the clutch pedal lever.
(c) Install the bolts and nuts.
Tightening torque: 30 N·m
(d) Put the pedal lever at the maximum stroke position and
connect it with the spring, in order to set the pedal to its
initial position.
2. Install the clutch pedal onto the 2 studs of the clutch
master cylinder.
Use a M13 wrench to tighten the clutch pedal brackets with
two M8 nuts.
Tightening torque: 23±3 N·m
3. Install the clutch master cylinder push rod with the U-
joint.
(a) Coat the contact areas between the center pin and the
U-joint pedal connector with multi-functional grease.
(b) In succession, join the U-joint (pedal connector) and
the clutch pedal lever with a cotter pin.
Caution: Insert the center pin into the pedal lever from
the left side of vehicle.
(c) Install the cotter pin onto the center pin.
4. Check and adjust the clutch pedal.
5. Connect the negative cable of the battery.
Bleed screw

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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.