Great Wall Florid, Руководство по обслуживанию

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103 Brake System
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 symptoms Causes Eliminating methods
Master cylinder's oil reservoir is
severely leaking
The 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 sufficient
2. No boost when the engine is off
3. 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
effect
1.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 braking 1. 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 clevis
Coupling nut
Rectangular sealing ring
Cylinder body
Fluid supply
sealing ring