BENDIX SD-08-2414 manual Bendix AD-IPAIR Dryer Troubleshooting Chart

BENDIX® AD-IP®AIR DRYER TROUBLESHOOTING CHART

SYMPTOMS	CAUSE	REMEDY
1. Air dryer is constantly	A. Excessive system leakage.	1.Test fittings, hoses, lines and connections. Apply
“cycling” or purging.	IMPORTANT: Note whether	soap solution to detect excessive leakage. Tighten or
Air dryer purges	air pressure loss is shown	replace as needed then repeat the air dryer charge-
frequently (every four	on dash gauge(s). Pressure	purge cycle and observe the gauge installed in the
(4) minutes or less	loss SHOWN on the gauges	supply reservoir. If leakage is within limits, remove
		the gauge from the reservoir and replace drain cock
while vehicle is idling)	is caused by service brake
		or valve. If excessive leakage is detected, continue
(continued).	system or component
		testing.
	leakage. Pressure loss
		2.Test the accessories connected to the supply
	NOT SHOWN on gauges is
		reservoir. Drain all air pressure from system,
	caused by supply system
		disconnect all air lines leading to accessories (fan
	or component leakage.
		clutch, wipers, air seats, etc.) and plug the reservoir
	(continued)
		at the disconnection point. Build the air system
		pressure until the air dryer purges and observe
		the supply reservoir gauge. If leakage is no longer
		excessive, repair or replace the leaking accessory.
		If excessive leakage is detected, continue testing.
		3.Test for governor leakage. Build the system pressure
		to the governor cut-out, turn off the engine and apply
		a soap solution to governor exhaust port and around
		the cap. Leakage should not exceed a one (1) inch
		bubble in five (5) seconds. Reduce the system
		pressure to 80 psi, or less, and re-apply the soap
		solution. Leakage should not exceed a one (1) inch
		bubble in five (5) seconds. If excessive leakage is
		detected in either test, repair or replace the governor.
		4.Test the compressor unloader leakage. Drain all air
		pressure from the system and remove the governor
		from the compressor. Temporarily plug the governor
		unloader port or air line that mated with, or connected
		to, the compressor. Build the air system pressure until
		the air dryer purges then IMMEDIATELY SHUT OFF
		THE ENGINE. Observe the air gauge in the supply
		reservoir. If the leakage is within limits, replace the
		compressor unloaders. Re-connect the governor to
		the compressor (after removing the plug installed in
		the governor) and retest while observing the supply
		reservoir gauge. If excessive leakage is detected,
		continue testing.
		5. Test the air dryer purge valve and outlet (delivery)
		check valve. Drain all air pressure from the system.
		Remove the control line connection at the air
		dryer and plug the end of the air line leading to the
		governor (not the air dryer control port). Build the
		system pressure to governor cut-out and observe the
		air gauge. If little or no pressure drop is observed,
		replace the air dryer check valve. If a pressure drop
		continues, apply a soap solution to the air dryer
		purge exhaust and purge control port (where the
		control line was removed). Leakage should not
		exceed a one (1) inch bubble in five (5) seconds.
		If leakage is excessive, repair or replace the purge
		valve assembly.

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