5
7. Insert relay piston spring (5) and relay piston in top end
of lower static piston, and primary circuit piston spring
(8) and primary circuit piston assembly in the bottom of
lower static piston.
8. Install stem bolt through bore of relay piston, invert entire
lower static piston assembly and position over a
screwdriver mounted in a vise. Engage screwdriver blade
in slot in head of stem.
9. Depress primary circuit piston assembly against spring
until locking groove is accessible through rectangular
hole in side of lower static piston. Engage a screwdriver
or wire in locking groove and release pressure on piston.
10. Install stem spring, (23), spring seat, (15) and stem nut,
(14). Torque to 20-30 inch Ibs.
11. Install lower static piston assembly in valve body. Install
retainer, (18), making certain locking tabs engage boss
on valve body.
PEDAL ASSEMBLY
Install pedal assembly using three cap screws. Check to be
certain plunger is in contact with spring seat. The stop but-
ton should be adjusted so that the roller and plunger contact
after adjustment, roller should be able to be turned freely by
thumb.
SERVICE CHECKS
OPERATING
Check the delivery pressure of both primary and secondary
circuits using accurate test gauges. Depress the pedal 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 proportionately with the
movement of the brake pedal.
When the treadle is fully applied, the reading on the test
gauge should fall off to zero promptly when the application
is released. It should be noted that the primary circuit delivery
pressure will be about 2 psi greater than secondary circuit
delivery pressure with primary and secondary circuit supply
reservoirs at the same pressure. This is normal in this valve.
LEAKAGE
1. Make and hold full brake application.
2. Coat the exhaust port and body of the brake valve with
soap solution.
3. Leakage not to exceed a 1” bubble in 3 seconds in both
the applied and released position.
If the brake valve does not function as described above or
leakage is excessive, it is recommended that it be replaced
with a genuine Bendix new or remanufactured unit, available
at your local authorized Bendix parts outlet.
FIGURE 3 - TYPICAL PIPING SCHEMATIC
QUICK
RELEASE
VALVE
TP-5
™
TRACTOR
PROTECTION VALVE
MV-3
™
MANIFOLD
VALVE
BRAKE
CHAMBER
SLACK
ADJUSTER
COMPRESSOR
SUPPLY
RESERVOIR
#1 SERVICE
RESERVOIR
#2 SERVICE
RESERVOIR
DOUBLE
CHECK
VALVE
SPRING
BRAKES
SLACK
ADJUSTER
DUAL BRAKE
VALVE
TRAILER
CONTROL
VALVE
BP-R1
™
BOBTAIL
PROPORTIONING
VALVE
AIR DRYER
