Bendix® AD-9® AND AD-9® IPC AIR DRYER TROUBLESHOOTING CHART
SYMPTOMS | CAUSE | REMEDY | ||
4. Safety valve on air dryer | A. | Restriction between air dryer and | A. | Check to determine if air is reaching supply reservoir. Inspect |
“popping off” or exhausting |
| supply (first) reservoir. |
| for kinked tubing or hose. Check for undrilled or restricted hose |
air. |
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| or tubing fittings and repair or replace as needed. |
| B. | Air dryer safety valve malfunction. | B. | Verify relief pressure is at vehicle or component manufacturer |
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| specifications. Replace if malfunctioning. |
| C. | Desiccant cartridge maintenance | C. Refer to Appendix A ,Table A and column 3. Check compressor | |
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| required. |
| for excessive oil passing and/or correct compressor installation. |
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| Repair or replace as necessary. Replace desiccant cartridge. |
| D. | Malfunctioning discharge check | D. Test to determine if air is passing through check valve. Repair | |
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| valve in end cover of the Benidix® |
| or replace. |
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| |
| E. | Excessive pressure pulsations | E. | Increase volume in discharge line by increasing length or |
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| from compressor. (Typical single |
| diameter. Add a ping tank (small reservoir). |
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| cylinder type). |
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| F. | Governor malfunction. Missing | F. | Test governor operation and/or inspect the control line leading |
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| or restricted governor control line |
| from the governor UNL (unloader) port to the air dryer control |
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| installation. |
| port. |
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5. Constant exhaust of air at air | A. | Air dryer purge valve leaking | A. | With compressor loaded, apply soap solution |
dryer purge valve exhaust. |
| excessively. |
| on purge valve exhaust, to test for excessive leakage. Refer |
(Charge mode.) |
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|
| to Technical Bulletin |
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| necessary. |
| B. | Compressor fails to unload (stop | B. | Confirm failure to unload by increasing & decreasing engine |
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| compressing air) and air dryer |
| RPM and noting change in the rate of leakage and intensity |
|
| purge exhaust makes “sputtering” |
| of accompanying leakage sound. Repair/replace compressor |
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| or “popping” sound. |
| unloaders. |
| C. Purge control line connected | C. Purge control line must be connected to unloader port of | ||
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| to reservoir or exhaust port of |
| governor. |
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| governor. |
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| D. Purge valve frozen open - | D. | Test heater and thermostat as described in Preventive | |
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| malfunctioning heater and |
| Maintenance Section. |
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| thermostat, wiring, blown fuse. |
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| E. | Excessive system leakage. | E. | See Symptom #1. |
| F. | Purge valve stays open - supply air | F. | Repair purge valve and housing. |
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| leaks to control side. |
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6. Can not build system air | A. | Inlet and outlet air connections | A. | Connect compressor discharge to air dryer supply port. |
pressure. |
| reversed. |
| Reconnect lines properly. |
| B. | Check valve between air dryer and | B. | Test check valve for proper operation. Repair or replace as |
|
| first reservoir. |
| necessary. |
| C. Kinked or blocked (plugged) | C. Check to determine if air passes through discharge line. Check | ||
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| discharge line. |
| for kinks, bends, excessive carbon deposits, or ice blockage. |
| D. Excessive bends in discharge line | D. Discharge line should be constantly sloping from compressor | ||
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| (water collects and freezes) |
| to air dryer with as few bends as possible. |
| E. | Refer to Symptom 4, Causes E & | E. | Refer to Symptom #4, Remedies E & F. |
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| F. |
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