AD-4™ AIR DRYER TROUBLESHOOTING CHART
SYMPTOMS | CAUSE | REMEDY | |
1. Dryer is constantly | A. Excessive system | A. If leakage IS SHOWN on gauges test for | |
“cycling” or purging. | leakage. | excessive service brake system leakage. | |
Dryer purges frequently | IMPORTANT: Note whether | Allowable leakage: | |
(every 4 minutes or less | |||
air pressure loss is shown | Single vehicle - 1 psi/minute either service | ||
while vehicle is idling). | |||
on dash gauge(s). Pressure | |||
reservoir. | |||
| |||
| loss shown on gauges is | ||
| Tractor trailer - 3 psi/minute either service | ||
| caused by service brake | ||
| reservoir. Repair and retest as required. | ||
| system or component | ||
|
| ||
| leakage. Pressure loss NOT |
| |
| SHOWN on gauges is |
| |
| caused by supply system or |
| |
| component leakage. |
|
B. If leakage is NOT SHOWN on gauges test for excessive supply system leakage.
Remove drain cock or valve in supply reservoir (wet tank) and install air gauge. Build system pressure, allow air dryer to purge and observe air gauge in supply reservoir. Pressure drop should not exceed 1 psi per minute. Perform tests 1 to 6 in the order
presented.
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