Service checks – Bendix Commercial Vehicle Systems E-7 DUAL BRAKE VALVE User Manual

Page 5

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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

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