10
Caution: While performing service on the AD-SP
™
air dryer, it
is not recommended that a clamping device (vise,
C-clamp, etc.) be used to hold any die cast aluminum
component as damage may result. To hold the body, install a
pipe nipple in the supply port and clamp the nipple into a vise.
DISASSEMBLY - TURBO CUT-OFF VALVE
1. Loosen the supply port line and allow any residual air in
the discharge line to drain.
2. Remove the retaining ring from the body assembly, then
remove the turbo cut-off cap from the body. Remove the
turbo cut-off cap o-ring.
3. Remove the turbo cut-off piston from the body.
4. Remove the large and small diameter o-rings from the
piston.
DISASSEMBLY - PURGE/RELIEF VALVE
1. If so equipped, disconnect, remove and save the exhaust
line from the exhaust port of the air dryer.
2. Remove the retaining ring from the body assembly, then
remove the non-metallic exhaust cover and spring from
the body. Note: The spring exerts a 30 pound force
against the exhaust cover.
3. Carefully remove the purge piston from the body and
remove the o-ring from the purge piston.
4. The purge valve has two different sides. Note which side
is visible before removing the valve. Remove the valve
from the body.
DISASSEMBLY - HEATER AND THERMOSTAT
1. Disconnect the vehicle wiring harness connector that
mates with the heater and thermostat connector on the
body. Pry the lock tabs out, on the vehicle wiring harness
connector, before removal from the air dryer connector.
Make sure connector seal is present on the vehicle wiring
harness connector.
2. Remove the retaining ring that secures the heater and
thermostat in the body.
3. Carefully pull the heater and thermostat assembly straight
out of the body.
4. Remove the o-ring from the heater connector.
DISASSEMBLY - DESICCANT CARTRIDGE
1. Place a strap wrench or equivalent tool on the desiccant
cartridge next to the lip low on the cartridge and rotate
counter clockwise to remove the desiccant cartridge.
CLEANING, INSPECTION AND ASSEMBLY
PREPARATION
1. Clean the exterior of the body.
2. Using a clean rag, wipe the body bores clean.
3. Inspect for physical damage to the body casting, broken
and or missing parts.
4. Inspect the interior and exterior of the body for severe
corrosion, pitting and cracks. Superficial corrosion and
or pitting on the exterior portion is acceptable.
5. Inspect the bores, valve seating and o-ring contact areas
for deep scuffing or gouges or nicks that would not permit
an air tight seal.
6. Inspect the pipe threads in the body. Make certain they
are clean and free of thread sealant.
7. Inspect the purge valve piston seat for nicks and
excessive wear.
8. Inspect all air line fittings for corrosion. Clean all old
thread sealant from the pipe threads.
9. All o-rings removed should be discarded and replaced
with new o-rings provided in appropriate kit(s).
10. Lubricate the body bores and o-ring grooves, in the body
and components, with a silicone grease only such as
those packaged with Bendix maintenance kits.
11. Lubricate all o-rings with a silicone grease only, such as
those packaged with Bendix maintenance kits.
Any component exhibiting a condition described in step 3
to 8 should be replaced.
ASSEMBLY - TURBO CUT-OFF VALVE
1. Lubricate all o-rings with a silicone grease only, such as
those packaged with Bendix maintenance kits.
2. Install the large and small diameter o-rings on the piston.
3. Install the turbo cut-off piston assembly in the body.
4. Install the o-ring on the turbo cut-off cap then install the
cap in the body.
5. Install the retaining ring in the body, making certain that
it is fully seated in its groove.
6. Before placing vehicle back into service, perform the
Operation & Leakage Tests stated elsewhere in this
manual.
ASSEMBLY - PURGE/RELIEF VALVE
1. Lubricate the piston o-ring with a silicone grease only,
such as those packaged with Bendix maintenance kits.
Also lubricate completely around the outside edge of
the purge valve.
2. Install the purge valve in the body making certain that it
is firmly and squarely seated in the body with the correct
side visible. Note: The three "bumps" on the purge valve
should not be visible. If the 3 "bumps" are visible after
the purge valve is installed, the valve must be removed
and re-installed.
