Bendix Commercial Vehicle Systems AD-9 AND AD-9 IPC AIR DRYERS 4/11 - Manual (Page 12)

12
Silencer Removal
If the air dryer purge valve has a silencer attached to it,
identify the style of silencer before attempting to remove
it. There are two different styles of silencers that have
been used with the Bendix
® AD-9 ® air dryer. One design
is secured to the air dryer purge valve adapter with four
cap screws that are visible from the bottom. The other is
a snap-on design. See Figure 8, illustration G.
Screw Mounted Silencer
1. Remove the four screws that secure the exhaust cover,
silencer cover, fi lter and silencer body to the adapter.
2. Remove the three screws that secure the adapter to
the purge valve. Remove the adapter and gasket.
Snap-on Silencer
1. Firmly grip the silencer and pull it away from the air
dryer end cover.
2. Slide the adapter off of the exhaust cover.
3. Remove the three screws that secure the exhaust cover
to the purge valve housing assembly of the end cover.
Remove the exhaust cover and gasket.
Purge Valve Removal
1. Remove the three 1/4" screws that secure the purge
valve housing assembly to the end cover assembly. Pull
the purge valve housing assembly out of the end cover
assembly. Remove the three o-rings from the exterior
of the purge valve housing assembly. (The medium
o-ring is not included in DLU models.) The o-rings may
be lodged in the end cover bores, if so, they must be
removed. Refer to Figure 8, illustration J.
2. Purge Valve Disassembly:
Note: In some cases a fl at (non-extended) exhaust
cover is used. If an extended type exhaust cover is in
use, (to accommodate the attachment of an exhaust
hose), the exhaust cover must be carefully peeled off of
the purge valve housing. Use a thin fl at blade to pry
the exhaust cover off, taking care not to damage
the potting material (RTV sealant) under the cover.
Removal of the piston from the purge valve housing
assembly requires a tool to hold the head of the purge
piston while unscrewing the purge valve shoulder
bolt. Remove the piston from the purge valve housing
assembly using a twelve point 1/4" socket to hold the
head of the purge valve shoulder bolt. See Figure 7,
illustration D.
A. Secure the top of the purge piston assembly using
the two opposing cast indentations and a removal
tool. Remove the purge valve shoulder bolt from
the bottom of the purge valve housing assembly.
Remove the exhaust guide and purge valve from
the purge valve housing.
B. Remove the purge piston assembly and return
spring from the opposite end of the purge valve
housing assembly. Remove the quad ring from the
purge piston assembly.
FIGURE 10 - HEATER & THERMOSTAT REMOVAL & INSTALLATION
RUBBER CUSHION
PURGE VALVE
W/HEATER & THERMOSTAT INSTALLED
(SECTIONAL VIEW FROM BOTTOM)
THERMOSTAT
HEATER
ELEMENT
RUBBER CUSHION
THERMOSTAT
HEATER
ELEMENT
Step B
Step A
PURGE VALVE HOUSING W/HEATER & THERMOSTAT
(SECTIONAL VIEW FROM BOTTOM)
PURGE
VALVE
ASSEMBLY
SMALL
O-RING
LARGE
O-RING
MEDIUM
O-RING
SCREW
HEATER &
THERMOSTAT
SEALING
RING
HEATER &
THERMOSTAT
SEALING RING
SEALING RING
HEATER &
THERMOSTAT
SEALING RING
PURGE VALVE
ASSEMBLY