BENDIX SD-08-2433 manual Refer to the Bendix Air Dryer Application Guideline BW2600

BENDIX®AD-9si™AIR DRYER

TROUBLESHOOTING CHART

SYMPTOM		CAUSE		REMEDY
2. Water in vehicle reservoirs.	A.	Maximum air dryer inlet temperature is	A.	Check for excessive carbon build-up in compressor discharge
		exceeded due to improper discharge		line. Replace if required. Make certain that discharge line
		line length.		length is at least 6 ft. Increase discharge line length and/or
				diameter to reduce air dryer inlet temperature.
	B.	Ambient temperature exceeds 125°F.	B.	Relocate the air dryer away from excessive heat source.
	C.	Air system charged from outside	C.	If system must have outside air fill provision, outside air should
		air source (outside air not passing		pass through the air dryer.
		through air dryer).
	D.	Excessive air usage - Air dryer not	D.	Refer to the Bendix® Air Dryer Application Guideline (BW2600)
		compatible with vehicle air system		for proper application of the Bendix® AD-9si™air dryer. An
		requirement (improper air dryer/		extended purge reservoir may be added for higher air usage
		vehicle application).		vehicles, such as city buses and construction vehicles.
				If the vehicle is equipped with high air usage accessories
				such as trailer pump-off systems or central tire inflation, the
				air for these accessories must by-pass the air dryer.
	E.	Desiccant requires replacement.	E.	Replace desiccant cartridge assembly. See Bendix Air Dryer
				Application Guideline (BW2600) for recommended service
				intervals.
	F.	Air dryer not purging.	F.	Refer to Symptom 6.
	G.	Purge (air exhaust) time insufficient	G.	Refer to Symptom 1.
		due to excessive system leakage.
3. Safety valve on air dryer	A.	Safety valve setting too low (<150 psi).	A.	Replace safety valve.
“popping off” or exhausting	B.	System pressure too high (>135 psi).	B.	Test with accurate gauge. Replace the governor cartridge if
air.				necessary.
	C.	Excessive pressure pulsations from	C.	Increase the volume in the discharge line. This can be
		compressor. (Typical single cylinder		accomplished by adding a 90 cubic inch (or larger) reservoir
		type).		between the compressor and the AD-9si air dryer.
4. Constant exhaust of air at air	A.	Air dryer purge valve leaking	A.	With compressor loaded, apply soap solution on purge valve
dryer purge valve exhaust		excessively.		exhaust, to test for excessive leakage. Repair or replace
or unable to build system				purge valve as necessary.
pressure. (Charge mode.)	B.	Purge valve frozen open - faulty heater	B.	Refer to paragraph 5 of the Operation and Leakage Tests for
		and thermostat, wiring, blown fuse.		heater and thermostat test.
	C.	Defective AD-9si™air dryer delivery	C.	Refer to Symptom 1, Remedy B.
		check valve.
	D.	Leaking turbo cut-off valve.	D.	Repair or replace purge valve assembly.
	E.	Defective governor.	E.	Check the governor at both “cut-in” and “cut-out” positions
				for proper pressures and excessive leakage at the exhaust.
	F.	Leaking purge valve control piston	F.	Repair or replace purge valve assembly.
		seals.

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