Parking Brake System - Chery automobile Service Manual

INSPECTION OF VACUUM BOOSTER
Inspection of brake performance
The driver will feel the brake pedal difficult to step down and its resistance force
considerably increase compared with normal condition when he step it after the vacuum
booster fails. In this case, the booster assy. shall be replaced in time. The condition of
vacuum booster is also determined in accordance with the following convenient method:
-- Shut down the engine, and forcefully step on the brake pedal several times to remove the
vacuum kept inside the vacuum booster.
-- Step on the brake pedal with the appropriate force to make the pedal kept in proper
position.
-- Start up the engine. If you feel the brake pedal fall down automatically and considerably
(force increase), it shows that the function of vacuum booster is normal; if the pedal is no
reaction, and nor force increase, it exhibits that the booster has failed, and the booster shall
be replaced.
-- Replace the booster assy., and, at the same time, replace the gasket. The tightening torque
of the booster assy. and master brake cylinder retaining nut is 20±2 N* m.
Inspection of the check valve of booster vacuum hose
The check valve of vacuum booster is installed in the vacuum hose. If the check valve
failure, the driver will feel the brake pedal difficult to step down, with the feeling of failure
to step it down to its limit, and the subsequent braking performance decreases evidently.
Blow the compression air in accordance with the direction of arrow on the check valve body
when inspecting the check valve, and the air is available to pass through; and don't pass
through if blowing the air in the reverse direction. Its one-way through is also inspected
using the mouth suction method. Replace the vacuum hose assy. if the check valve is badly
sealed.
The parking brake is realized by adding a set of manual operating mechanism on the
rear wheel brake, as shown in the figure below. Due to the common use of a set of brake with
the rear wheel brake, it simplifies the structure and reduces the weight.

PARKING BRAKE SYSTEM

P-17