TM 5-3810-307-24-1-1
The air dryer consists of a desiccant cartridge and
2.
With the engine still running, perform a series
a die cast aluminum end cover secured to a
of brake applications to reduce the air pressure and
cylindrical steel outer shell with eight capscrews
observe the pressure when the governor cuts-in the
and nuts. The end cover contains a check valve
compressor. The cut-in pressure is 105 psi (7239
assembly, a safety valve, three threaded air
kPa) Never adjust the governor pressure settings
connections and the purge valve housing
unless they are checked with a gauge that is known
assembly. The removable purge valve housing
to be accurate If it has been determined that the
assembly incorporates a purge valve mechanism
pressure settings of the governor must be changed,
and a turbo charger cutoff feature that is designed
the procedure is as follows:
to prevent loss of engine turbo boost pressure
during the purge cycle of the air dryer. For ease of
a.
Unscrew the cover at the top of the
serviceability, the desiccant cartridge and
discharge check valve assembly are screw-in type.
governor.
The purge valve housing assembly, which includes
the heater and thermostat assembly, and the
b.
Loosen the adjusting screw locknut.
discharge check valve assembly, is serviceable
from the exterior of the air dryer, while servicing the
c.
Turn the adjusting screw counter-
screw-in desiccant cartridge requires removal of
clockwise to raise the pressure settings and
the air dryer assembly from the crane.
clockwise to lower the pressure setting.
Removal
d.
Tighten the adjusting screw locknut to
lock the adjustment.
1.
Chock the wheels.
3.
Repeat Step 2 as necessary.
2.
Deplete the pressure in both air systems.
Leakage Test
3.
Ensure the ignition switch is in the OFF
position.
1.
Leakage checks on the governor are made at
its exhaust port in both the cut-in and cut-out
4.
Tag and disconnect the air lines from the
positions. In the cut-in position, check the exhaust
dryer.
port for inlet valve leakage by applying a soap
solution at the port. Leakage could also be through
5.
Disconnect the electrical lead from the bottom
the bottom piston grommet. In the cut-out position,
of the dryer.
check the exhaust port to determine leakage at the
exhaust valve seat or stem grommet. In this
6.
Remove four bolts, lockwashers, and nuts
position, leakage could also be through the upper
attaching the dryer to the chassis frame and remove
piston grommet.
the dryer.
2
If the governor does not function as described,
7.
If the dryer is to be replaced with a new one,
or if leakage is excessive, it is recommended that it
remove the fittings from the dryer ports.
be repaired or replaced. Refer to the Parts Manual.
NOTE
AIR DRYER
The dryer does not have to be removed
to disassemble it.
Description
Installation
The function of the air dryer is to collect and
remove air system contaminates in solid, liquid, and
1.
Install the fittings in the dryer ports.
vapor form before they enter the brake system. It
provides clean, dry air to the components of the
2.
Position the air dryer on the mounting bracket
brake system which increases the life of the system
and secure it with the four bolts, lockwashers, and
and reduces maintenance costs.
nuts.
3.
Connect the electrical lead to the connection
on the bottom of the dryer.
2-7-12 C-1
