Specifications

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control valve push rod 1 and piston 5 shift backward, the air valve 4 keeps away from
the vacuum valve port. Thus the brake process ends.
4.3.2 Assembly of vacuum booster and master cylinder
(1) Assemble the bolt of the vacuum booster and installation bracket on the truck
frame, connect the adjusting fork on the end of the vacuum booster with the link lever
of the brake pedal, tighten the nut with torque 12N.m-18N.m.
(2) Connect the vacuum tube with the tube connector to offer air tightness.
(3) Screw the brake oil pipe into oil outlet of the master cylinder with the torque of
12N.m to 16N.m.
(4) Open the cover of the fluid tank and add brake fluid, discharge the air of the
brake system.
(5) When only replace the master cylinder or the vacuum booster, the tightening
torque of the attachment nut is 12N.m to 18 N.m.
(6) Please don’t adjust the pull rod head between the vacuum booster and the
master cylinder.
4.3.3 Points for attention
(1) Use specified brake fluid in the manual.
(2) After adding brake fluid into the system, must discharge the air in the pipe.
(3) After discharging the air, the fluid level of the fluid tank should be at the middle
position.
(4) If the trouble listed in the following list occurred, only qualified person shall be
permitted to repair.
Problem
Possible cause
Poor braking effect due to no oil
pressure.
1. Worn cylinder ring.
2. Damaged oil pipeline
Oil pressure is too low, pedal
force becomes heavy
1. Air leaks of vacuum booster
2. Air leaks of engine air pipe
Lacking oil in storage oil tank
1. Fluid leaks from the cylinder conjunction
place
2. Worn piston ring
Soft or low brake pedal
1. Air mixed in brake system
2. Improper clearance between push rod and
piston.