Bendix Commercial Vehicle Systems AD-RP PuraGuard Oil Coalescing Remote Purge Air Dryers - Manual (Page 16)

16
Bendix ® AD-RP ™ AIR DRYER TROUBLESHOOTING CHART
SYMPTOMS CAUSE REMEDY
1. Air dryer is constantly
“cycling” or purging.
Air dryer purges
frequently (every 4
minutes or less) while
vehicle is idling.
A. Excessive system leakage.
IMPORTANT: Note whether
air pressure loss is shown
on dash gauge(s). Pressure
loss shown on the gauges
is caused by service brake
system or component
leakage. Pressure loss NOT
SHOWN on the gauges is
caused by supply system or
component leakage.
A. If leakage IS SHOWN on the gauges, test for
excessive service brake system leakage.
Allowable leakage:
Single vehicle - 1 psi / minute per service reservoir.
Tractor Trailer - 3 psi / minute per service reservoir.
Repair and retest as required.
If leakage is NOT SHOWN on gauges, test for
excessive supply system leakage.
Remove the drain cock, or valve, in the supply
reservoir (wet tank) and install an air gauge. Build
the system pressure, allow the air dryer to purge.
Observe the air gauge in the supply reservoir. The
pressure drop should not exceed 1 psi per minute.
Perform the following tests (1 to 5) in the order
presented.
(continued)