Bendix® AD-9®AND AD-9®IPC AIR DRYER TROUBLESHOOTING CHART

SYMPTOMS

CAUSE

REMEDY

7. Air dryer does not purge or

A.

Missing, broken, kinked, frozen,

A. Inspect control line from governor UNL (unloader) port to control

 

exhaust air.

 

plugged or disconnected purge

 

port of air dryer. Test to determine if air flows through purge

 

 

 

control line.

 

control line when compressor unloaded. Check for undrilled

 

 

 

 

 

fittings. (See Symptom #4, Remedy C.)

 

 

B.

Faulty air dryer purge valve.

B.

After determining air reaches purge valve (Remedy A above),

 

 

 

 

 

repair purge valve.

 

 

C.

See Causes, B, E, G for Symptom

C.

Refer to Remedies B, E, G for Symptom #4.

 

 

 

#4.

 

 

8.

Desiccant material being

A.

This symptom is almost always

A.

See Causes and Remedies for Symptoms 1, 2, 3, 4 and 5.

 

expelled from air dryer purge

 

accompanied by one or more of

 

 

 

valve exhaust (may look like

 

Symptoms 1, 2, 3, 4 and 5. See

 

 

 

whitish liquid or paste or

 

related causes for these symptoms

 

 

 

small beads.)

 

above.

 

 

 

- OR -

B.

Air dryer not securely mounted.

B.

Vibration should be held to minimum. Add bracket supports or

 

Unsatisfactory desiccant life.

 

(Excessive vibration.)

 

change air dryer mounting location if necessary.

 

 

C.

Malfunctioning or saturated

C.

Replace desiccant cartridge assembly.

 

 

 

desiccant cartridge.

 

 

 

 

D.

Compressor passing excessive oil.

D. Check for proper compressor installation; if symptoms persist,

 

 

 

 

 

replace compressor.

 

 

E.

Desiccant cartridge not assembled

E.

C h e c k t h e t o r q u e o n t h e d e s i c c a n t c a r t r i d g e

 

 

 

properly to end cover. (Loose

 

to end cover attachment. Refer to assembly section of this

 

 

 

attachment)

 

data sheet.

9.

“Pinging” noise excessive

A.

Defective check valve assembly in

A.

Refer to Remedy C, Symptom #1.

 

during compressor loaded

 

air dryer end cover.

 

 

 

cycle.

 

 

 

 

 

 

B.

Leaking Turbo Cut-off valve.

B. Repair or replace purge valve assembly.

 

 

 

 

 

 

 

 

C.

Leaking purge valve control piston

C.

Repair or replace purge valve assembly.

 

 

 

o-ring.

 

 

10. Constant seepage of air at

A.

Defective check valve assembly in

A.

Refer to Remedy C, Symptom #1.

 

air dryer purge valve exhaust

 

air dryer end cover.

 

 

 

(non-charging mode.)

B.

Leaking Turbo Cut-off valve.

B. Repair or replace purge valve assembly

 

 

C.

Leaking purge valve control piston

C.

Repair or replace purge valve assembly.

 

 

 

o-ring.

 

 

11.

The air dryer purge piston

A.

Compressor fails to “unload”.

A.

Faulty governor installation; no air line from governor to

 

c y c l e s r a p i d l y i n t h e

 

 

 

compressor or line is kinked or restricted. Install or repair air

 

compressor unloaded (non-

 

 

 

line.

 

compressing) mode.

 

 

 

 

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BENDIX SD-08-2412 manual Bendix AD-9AND AD-9IPC AIR Dryer Troubleshooting Chart