Refer to Fig. 10 for numbers in parenthesis.
After valve is disconnected and removed from the
vehicle, remove treadle assembly or mounting bracket.
Inspect valve for damage. If a valve body casting is
broken or shows cracks, replace valve.
Mark relative location of primary and secondary
valve bodies (21 and 4) for alignment purposes
secondary valve body (21) from primary valve
Remove piston (23), spring (22) and O-ring (11)
from secondary valve body (21).
Remove retaining ring (18) which secures
exhaust valve body (12) in secondary valve body
Remove exhaust valve body (12), spring (20),
valve (16) and O-ring (19) from valve body.
Remove O-ring (24) from secondary piston (23).
Remove screw (14), washer (15) and diaphragm
(13) from exhaust valve body (12).
Remove O-ring seal (17), seal retainer (8) and
rubber seal from valve (16).
Remove retaining ring (26) from primary valve
Remove exhaust valve body (9), spring (20) and
valve (29) from primary valve body (4).
Remove O-rings (17 aid 10) from exhaust valve
Remove O-ring (27), seal retainer (8) and rubber
seal from valve (29).
retaining ring (3), Then remove piston (31) and
spring (7) from primary valve body (4).
Remove O-ring (5) from piston (31).
Place piston (31) in a suitable fixture so that
spring retainer (1) which is spring loaded can be
depressed approximately 267 N (60 lbf).Be sure
to protect primary piston exhaust seat "B" from
Remove retaining ring (2) from piston (31) and
carefully release force on spring retainer (1).
Remove spring retainer (1), spring (32), reaction
ring (6) and shims (30) from piston.
CLEANING AND INSPECTION
Wash all metal parts in cleaning solvent and then dry.
Wipe all rubber parts clean for inspection.
Examine rubber seals, O-ring, reaction ring and exhaust
port diaphragm. O-ring seals must not be cut or show
surface nicks or gouges. Diaphragm (13) should be
flexible and show no cuts, tears or distortion. Rubber
seals for inlet valves (16 and 29) must be smooth on
valve face area. There must not be any nicks, cuts,
dents or imperfections visually evident in the rubber.
Reaction ring (6) must not be cut, distorted or show nicks
Examine exhaust valve bodies (12 and 9), pistons (23
and 31) and valve bodies (4 and 21). Castings must be
free of cracks and voids. All surfaces for O-rings must
be smooth, round and free of deep scratches, dents or
gouges. There must be no evidence of metal-to-metal
galling of aluminum surfaces. Valve body flanges,
threads and retaining ring grooves must not be distorted.
Inlet seats in valve bodies (4 and 21) and exhaust seats
"B" and "G" on pistons (31 and 23) must be smooth and
free from cracks or gouges. Examine springs, spring
retainer (1), retaining rings and screws. Parts should be
free of distortion and corrosion. Replace any parts that
are not considered serviceable. It is recommended that
parts supplied in the service repair kit be used.
Lubricate the inside diameter of primary piston (31),
where spring retainer (1) is guided, with Item 1 in
LUBRICANT SPECIFICATIONS, as well as all other
seals and sliding surfaces.
Install diaphragm (13), washer (15) and screw
(14) to exhaust valve body (12). Tighten screw to
.6 - .9 N.m (6 - 8 in lbs) torque.
Install new rubber seal onto new valve (16).
Install new O-ring (17) onto valve (16) and place
seal retainer (8) over tube and around valve
CTS-4079-CHAPTER IV - Page 14