5-38. AIR DRYER-Continued
(3) Install the O-ring (8) on the check valve assembly (7), then install the assembly in the end cover using
a socket. Torque to 200-250 in lbs (23-28, Nm).
(4) Install the desiccant O-ring (29) in its groove in the end cover. Using a light coat of barium grease
(Item 51, Appendix E), lubricate the bottom of the desiccant cartridge in the area that will contact the
O-ring (29) and end cover (32). Screw the desiccant cartridge into the end cover until contact is made
between it and the O-ring. Using a strap to chain wrench positioned 2-3" (51-76 mm) from the bottom
of the cartridge, turn the desiccant cartridge clockwise 180-225 degrees beyond the position where
initial contact was made between the cartridge and end cover O-ring. Torque should not exceed 50 ft
lbs (68 Nm).
(5) Install the end cover outer housing O-ring (27) on the shoulder in the end cover (32). Place the housing
(25) over the desiccant cartridge and align the holes. Install the six cap screws (22), lock nuts (23) and
twelve special washers (24), making certain they are in the proper position as marked during
disassembly. The two longer cap screws (3) will be used to secure the air dryer to its mounting bracket.
Tighten the six cap screws and nuts in a star pattern depending on lower bracket location. Torque to
270-385 in lbs (31-43 Nm).
The two remaining bolt holes in the end cover and two cap
screws MUST be the ones marked during disassembly to assure
proper orientation of the ports and adequate length of the cap
(1) Install the assembled air dryer back onto the vehicle by slipping it into the upper mounting bracket (30).
Align the two unused holes in the end cover with the bottom mounting bracket (6) such that the bottom
bracket supports air dryer. The air dryer end cover (32) should rest on the bracket. Using the
remaining two cap screws (3), four special washers (5), and two lock nuts (4), secure the air dryer to the
lower bracket. Tighten the two remaining cap screws to 270-385 in lbs (31-43 Nm).
(2) Tighten the bolt (2), washer (33) and nut (34) on the upper mounting bracket (30). Torque to 80-120 in
lbs (9-13 Nm).
(3) Reconnect the three airlines to the proper ports on the end cover (identified during disassembly).
(4) Reconnect the vehicle wiring harness (1) to the air dryer heater and thermostat assembly connector by
plugging it into the dryer connector until its lock tab snaps in place.
Before placing the vehicle in service, perform the following
(1) Close all reservoir drain cocks.
(2) Build up system pressure to governor cut-out and note that air dryer purges with an audible escape of