PREVOST X3-45 Multiplex, Руководство по обслуживанию

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4
m a i n local global o p e r a t i o n t r o u b l e -
m e n u s e a r c h s e a r c h s h o o t i n g
Using light oil, lubricate the treadle roller, roller pin, and hinge
pin.
Check the rubber plunger boot for cracks, holes or deterio-
ration and replace if necessary. Also, check mounting plate
and treadle for integrity.
Apply 2 to 4 drops of oil between plunger and mounting
plate -
do not over oil!
Every year, or 100,000 miles, or 3,600 operating hours:
Disassemble, clean parts with mineral spirits, replace all
rubber parts, or any part worn or damaged. Check for proper
operation before placing vehicle in service.
SERVICE CHECKS
OPERATING CHECK
Check the delivery pressure of both primary and secondary
circuits using accurate test gauges. Depress the treadle to
several positions between the fully released and fully ap-
plied positions, and check the delivered pressure on the
test gauges to see that it varies equally and proportionately
with the movement of the brake pedal.
After a full application is released, the reading on the test
gauges should fall off to zero promptly. It should be noted
that the primary circuit delivery pressure will be about 2 PSI
greater than the secondary circuit delivery pressure with
both supply reservoirs at the same pressure. This is normal
for this valve.
Important:
A change in vehicle braking characteristics or a
low pressure warning may indicate a malfunction in one or
the other brake circuit, and although the vehicle air brake
system may continue to function, the vehicle should not be
operated until the necessary repairs have been made and
both braking circuits, including the pneumatic and mechani-
cal devices, are operating normally. Always check the vehicle
brake system for proper operation after performing brake
work and before returning the vehicle to service.
LEAKAGE CHECK
1. Make and hold a high pressure (80 psi) application.
2. Coat the exhaust port and body of the brake valve with a
soap solution.
3. Leakage permitted is a one inch bubble in 3 seconds. If
the brake valve does not function as described above or
leakage is excessive, it is recommended that it be re-
placed with a new or remanufactured unit, or repaired
with genuine Bendix parts available at authorized Ben-
dix parts outlets.
Refer to figures 4, 5 and 6 for item numbers referenced in
parenthesis.
REMOVAL
1. Chock the vehicle wheels or park the vehicle by
mechanical means. (Block and hold vehicle by means
other than air brakes.) Drain all air system reservoirs.
2. Identify and disconnect all supply and delivery lines at
the brake valve.
3. Remove the brake valve and treadle assembly from the
vehicle by removing the three cap screws on the outer
bolt circle of the mounting plate. The basic brake valve
alone can be removed by removing the three cap screws
on the inner bolt circle.
DISASSEMBLY
(Figures 4, 5 and 6)
1. If the entire brake valve and treadle assembly was re-
moved from the vehicle, remove the three cap screws
securing the treadle assembly to the basic brake valve.
2. Remove the screw (9) securing the exhaust diaphragm
(10) and washer (11) to the exhaust cover (12).
3. Remove the four screws that secure the exhaust cover
(12) to the lower body.
4. Remove the secondary inlet and exhaust valve assem-
bly (13) from the lower body.
5. Remove the four hex head cap screws securing the lower
body to the upper body and separate the body halves.
6. Remove the rubber seal ring (14) from the lower body.
7.
For E-8P only:
While applying thumb pressure to the
primary piston (22), lift out and up on the three lock tabs
of the primary piston retainer (15).
8.
For E-10P only:
While depressing spring seat (7), re-
move retaining ring (8). Remove spring seat (7) and coil
spring (5).
Caution:
Before proceeding with the disassembly, re-
fer to Figures 3 and 4 and note that the lock nut (16)
and stem (17) are used to contain the primary pis-
ton return spring (
for E-8P:
23,
for E-10P:
6), stem
spring (19), and the relay piston spring (21). The com-
bined force of these springs is approximately 50
pounds and care must be taken when removing the
lock nut as the spring forces will be released. It is
recommended that the primary piston and relay pis-
ton be manually or mechanically contained while the
nut and stem are being removed.
9. Using a 3/8” wrench, hold the lock nut (16) on the threaded
end of the stem (17). Insert a screwdriver to restrain the
stem, remove the lock nut (16), spring seat, (18) and
stem spring (19).
10.
For E-10P only:
Remove adapter (1) and o-ring (4).
Remove the primary piston (2) from adapter (1) and o-
ring (34) from the primary piston (2).