BENDIX SD-08-2412 manual Silencer Removal, Purge Valve Removal

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, filter 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 flat (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 flat 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.

SMALL
O-RING		HEATER &
MEDIUM	SCREW
		THERMOSTAT	Step B
O-RING
LARGE		Step A	SEALING RING
O-RING
	HEATER &	HEATER	RUBBER CUSHION
	SEALING THERMOSTAT	ELEMENT	THERMOSTAT
	RING
PURGE VALVE		PURGE	SEALING RING
	HEATER &	VALVE
ASSEMBLY		ASSEMBLY
	THERMOSTAT
	SEALING RING

HEATER

ELEMENT

RUBBER CUSHION
THERMOSTAT	PURGE VALVE HOUSING W/HEATER & THERMOSTAT
	(SECTIONAL VIEW FROM BOTTOM)

PURGE VALVE

W/HEATER & THERMOSTAT INSTALLED

(SECTIONAL VIEW FROM BOTTOM)

FIGURE 10 - HEATER & THERMOSTAT REMOVAL & INSTALLATION

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