Wash all remaining parts in a commercial
solvent making sure all surfaces, bores, ports
The heater and thermostat assembly in the AD-2
end cover are non-serviceable. Do not remove
the thermostat cover. Should this assembly
become defective, the end cover must be
Fig. 18 AD-2 End Cover Assembly with
Purge Valve Assembly Removed
Fig. 19 Purge Valve Assembly Disassembled
Lubricate the piston O-ring and install it on the
Lubricate the piston bore and install the piston.
Install the purge piston return spring and
Install the purge valve in the large cap nut so
that the rubber portion rests on the metal seat of
the cap nut.
Secure the valve to the piston using the 1/4"-20
capscrew and lockwasher and torque to 5.5 N.m
(50 in. lbs.).
Lubricate and install the two cap nut 0- rings.
Lubricate the cap nut threads and the cap nut
bore of the end cover and install the cap nut;
torque it to 19.8-27.5 N.m (180- 250 in. lbs.).
Secure the exhaust diaphragm to the exhaust
cover using the No. 6-32 phillips head screw and
Secure the exhaust cover to the purge valve hex
head cap nut using the No. 6-32 phillips head
Lubricate and install the large diameter 0- ring
around the end cover assembly.
OUTLET PORT CHECK VALVE ON AD-2
The one-way check valve located in the outlet port of
the AD-2 dryer assembly is replaced as a complete
assembly. The removal and installation procedure is as
follows (Refer to Fig.
Set parking brake by applying the control valve.
Fig. 20 Typical Air Dryer Installation
Check Valve Assy.
Supply to Air Reservoir
Pressure Relief Valve
Governor Control Line
Air Source From Compressor
Air Dryer Assembly
CTS - 4079 - CHAPTER XIV - Page 11