7 - 1 4 . Disconnect air line and push rod yoke. Re-
f. With the engine stopped and the pressure at
90-100 PSl (6.33-7.03 kg/cm2) make and hold a full
move nuts on mounting studs and remove air chamber.
s e r v i c e brake application.
A two minute check
7-15. BRAKE CHAMBER DISASSEMBLY:
should show a pressure drop of no more than 8 PSI
( . 5 6 k g / c m2) for the combination vehicle system.
a. Clean the exterior of the brake chamber.
g . If "f" indicates possible leakage, apply soap
b. Mark the parts so they can be reassembled the
suds on the RE-6 cover and exhaust port.
inch (25.4 mm) bubble in not less than three seconds
c. Pull out push rod and clamp it in this position
w i t h a vise or with vise grip pliers.
h. Place the tractor protection control valve in
should be taped to prevent damage to the push rod.
" e m e r g e n c y " p o s i t i o n or shut off cut-out cock on
t h e emergency line and disconnect the emergency
d. Remove the bolts on the clamp ring.
Trailer brakes must apply promptly.
C h e c k for leakage at the emergency coupling. A
e. Spread the clamp ring slightly to permit it to
leak indicates a leaking check valve or o-rings in
be removed. Be careful not to bend it out of shape.
the RE-6 valve. Also check for leakage on the ser-
A leak here indicates leaky o-rings on
f. Remove the pressure plate and diaphragm,
R e c h a r q e the svstem.
should release at 65 PSI (4.57 kg/cm2) e m e r g e n c y
g. Remove the locknut and yoke from the push rod.
S h u t off the engine with the system fully
h. Release the grip on the push rod.
Make a series of foot valve applications
to reduce the pressure to 30 PSI (2.11 kg/cm2) The
i. Remove the push rod and spring.
t r a i l e r brakes should apply automatically at this
pressure or at the emergency setting of the tractor
7 - 1 6 . CLEANING AND INSPECTION OF PARTS.
7 - 1 7 . Clean all metal parts in a suitable solvent.
7-8. If the valve does not function properly or leak-
a g e is excessive, it should be replaced.
replace if necessary.
BRAKE CHAMBER ASSEMBLY:
Stand the push rod assembly on a flat surface.
7-10. Air pressure on the pressure plate side of the
Put the return spring in position.
brake chamber diaphragm pushes the diaphragm a-
gainst the push rod assembly. This extension of the
Place the non-pressure plate over the push
push rod pushes against the slack adjuster, which
actuates the brakes.
7-11. BRAKE CHAMBER SERVICING.
Push the non-pressure plate down against the
flat surface and clamp in place with vise grip pliers
with taped grips.
7-12. If leakage is detected around the clamp ring,
i t may be tightened enough to stop the leakage.
e . Place the clamp ring over the non-pressure
Overtightening may cause permanent distortion of the
plate clamping surface.
T h e clamp ring bolts (2) on Bendix
Westinghouse air chambers can be tightened to 120-
f. Position the diaphragm in the pressure plate
130 inch-lbs. (1.38-1.50 kg-m)
and assemble with the non-pressure plate by work-
7-13. BRAKE CHAMBER REMOVAL.
ing the clamp ring over the pressure plate. Align all
marks made during disassembly.