Golden Dragon XML6125CLE, Repair Manual

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BR-18 Brake System BR-6125J93C-01
3)
Tightness test
Close the switches A1, A2, A3 and A4, open the switch A0. When the pressure in the gauge M0 is 1MPa, close
the switch A0. Maintain the pressure for five minutes; inspect the tightness of the assembly. The permissible
pressure drop is less than or equal to 10kPa.
3. Master valve of air brake
‹ Precautions for use and maintenance
1) The maximum free stroke of the brake pedal is generally 8~10mm, which is restricted by the contact between
the upper piston and the upper valve body in the brake valve. When the brake pedal is pressed down to its
limit, the pedal shall not impact on any other adjacent parts.
2) The adjusting screw is used to regulate the air exhaust gap (also called exhaust opening, whose rated value is
1.2±0.2mm,) which is set by the manufacturer before delivery, and generally shall not be adjusted randomly in
use.
3) The tightness of the dust shield on the tappet should be well kept so as to prevent any sands from entering the
brake valve, which may lead to a rough friction surface and difficult tappet movement, influencing the normal
work of the valve.
4) When the mileage reaches 48000Km, the brake valve should be disassembled, cleaned and adjusted by the
professional technician of repair shop. The O–seal rings should be replaced, the upper and lower valves
should be replaced if they have evident wear, and the upper and lower pistons and the relay piston should also
be adjusted if they are roughened.
5) The air bleeding in the upper and lower valves are mostly because there are sands or rust on the valve rubber
surface. They should be dismantled and cleaned with alcohol and leadless gasoline. The mineral oils (diesel
and engine oil) are strictly prohibited for their cleaning.
‹ Disassembly
1) To facilitate the re-installation, make a positional mark for each
part before dismantling.
2) Set the assembly on a vice clamp with copper or aluminum
protection.
3) Remove the four hex bolts 18 with a spanner and put those from
the upper part and those from the lower part separately.
4) Use snap ring pliers to remove the retainer ring for holes 29 ,
dust boot 28 and bushing 27 from the upper part of the upper
body 1.
5) Use snap ring pliers to remove the retainer ring for holes 26,
strut set 25, spring seat 24 and rubber spring 23.
6) Remove the piston 21 and spring 19 from the upper body 1 and
then the O-ring 22 and two pilot rings 20 from the piston.
7) Remove the retainer ring for holes 7, bushing 4, cone spring 3 and valve assembly 2 from the lower end of the
upper body 1, and then remove the internal and external O seals 5 and 6 from the bushing 4.
8) Remove the O seal ring 8 from the lower body 14.
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