Service manual

ManualsBrandsBENDIX ManualsDryerAD-1 AIR DRYER

AD-9

™

AIR DRYER TROUBLESHOOTING CHART

SYMPTOMS CAUSE

REMEDY

1. Test fittings, hoses, lines and connections.

Apply soap solution to detect excessive

leakage. Tighten or replace as needed then

repeat the air dryer charge-purge cycle and

observe the gauge installed in the supply

reservoir. If leakage is within limits remove gauge

from reservoir and replace drain cock or valve. If

excessive leakage is detected, continue testing.

2. Test accessories connected to supply

reservoir. Drain all air pressure from system,

disconnect all air lines leading to accessories

(fan clutch, wipers, air seats, etc.) and plug the

reservoir at disconnection point. Build air system

pressure until air dryer purges and observe

supply reservoir gauge. If leakage is no longer

excessive, repair or replace leaking accessory. If

excessive leakage is detected, continue testing.

3. Test governor leakage. Build system pressure

to governor cut-out turn off engine and apply

soap solution to governor exhaust port and

around cap. Leakage should not exceed a 1"

bubble in 5 seconds. Reduce system pressure

to 80 psi or less, and reapply soap solution.

Leakage should not exceed a 1" bubble in 5

seconds. If excessive leakage is detected in

either test, repair or replace governor.

4. Test compressor unloader leakage. Drain all

air pressure from 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 air

system pressure until air dryer purges then

IMMEDIATELY SHUT OFF THE ENGINE.

Observe the air gauge in the supply reservoir. If

leakage is within limits, replace the compressor

unloaders. Reconnect the governor to the

compressor (after removing plug installed in

governor) and retest while observing supply

reservoir gauge. If excessive leakage is

detected, continue testing.

5. Test air dryer purge valve and outlet

(delivery) check valve. Drain all air pressure

from 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 system pressure to governor cut-out

and observe air gauge. If little or no pressure

drop is observed replace the air dryer check

valve. If pressure drop continues apply soap