Service Manual

627333-A 8-13
Air Dryer
Remove four mounting bolts and valve housing
assembly. Spring and cap will fall out. Remove rubber
diaphragm. Clean and inspect diaphragm lip groove. If
groove is damaged so that a tight seal cannot be
maintained, replace air dryer. Install new diaphragm
with its lip in groove. DO NOT GREASE THE
DIAPHRAGM.
Install new spring and cap with cap lip facing out. Install
valve housing assembly with new lubricated O-ring and
filter over orifice. Install new mounting bolts and tighten
to 6 Nm (53 lbf in).
Purge Valve
FIG. 11: Purge valve is located on bottom of air dryer.
Purge valve remains open during a compressor unload
cycle. Purge valve allows collected moisture,
condensation, and contamination to be expelled from
air dryer during purge cycle.
The purge opens by gouvenor when the pressure
inside the tanks is to high. The pressure can be edit by
adjusting the purge valve.
Use grease included with replacement kit to lubricate
O-rings and seals. DO NOT grease rubber seat. If
shims are included in replacement kit, they must be
installed above and below spring. If they are not
included, they are not needed. Remove snap ring,
valve head and spring. Remove piston assembly from
base. Remove washer and O-rings from base. Clean
and inspect valve bore. If valve bore is damaged so
that a tight seal cannot be maintained, replace air dryer.
Apply a thin layer of grease to valve bore and to all
O-rings. Install new washer and O-ring in dryer base
and on valve head. Assemble piston assembly. Install
O-ring in groove on piston head. Install piston seat in
groove on piston base. Install washer on piston.
NOTE: Lip on washer must face piston seat.
Install spring in valve head; fit valve head assembly into
bore and insert snap ring.
NOTE: Make sure snap ring is fully seated or
assembly will leak from purge valve.
FIG. 11
M6215006