BENDIX AD-9 AIR DRYER

Questions and Answers

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rowejeromeAug 1, 2025
How to fix constant exhaust of air at the purge valve of my BENDIX Dehumidifier?
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  scottdawnAug 1, 2025
  If there's a constant exhaust of air at the air dryer purge valve exhaust of your BENDIX Dehumidifier (charge mode), here's what you can check: * The air dryer purge valve may be leaking excessively. Apply a soap solution to the purge valve exhaust to test for leakage and repair as needed. * The compressor might fail to unload, causing a sputtering or popping sound. Confirm this by varying the engine RPM and noting changes in the leakage rate and sound. Repair or replace the compressor unloaders.
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Tiffany WilliamsAug 13, 2025
Why can't my BENDIX Dehumidifier build system air pressure?
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  Veronica RojasAug 13, 2025
  If your BENDIX Dehumidifier can't build system air pressure, consider these potential causes: * The inlet and outlet air connections might be reversed; connect the compressor discharge to the air dryer supply port correctly. * The check valve between the air dryer and the first reservoir might be faulty; test and repair or replace it as necessary. * The discharge line could be kinked or blocked; check for any obstructions, bends, carbon deposits, or ice blockage. * Excessive bends in the discharge line can cause water to collect and freeze; ensure the line slopes from the compressor to the air dryer with minimal bends.
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Michele MillerAug 19, 2025
Why is my BENDIX Dehumidifier constantly cycling or purging?
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  Lawrence LongAug 19, 2025
  Your BENDIX Dehumidifier might be constantly cycling or purging due to excessive system leakage. If gauges show leakage, test for excessive service brake system leakage, repair, and retest as needed. If leakage isn't shown on gauges, test for excessive supply system leakage by installing an air gauge in the supply reservoir and observing the pressure drop, which should not exceed 1 psi per minute. Perform tests 1 to 6 in the order presented.
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christina04Oct 25, 2025
What to do if there is water in the vehicle reservoir of my BENDIX Dehumidifier?
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  George GonzalezOct 25, 2025
  If you find water in the vehicle reservoir of your BENDIX Dehumidifier, consider the following possibilities: * The desiccant cartridge may need replacement due to excessive contaminants. * The discharge line might be of improper length or material, or the air dryer inlet temperature may be exceeded. Check the air line connections, size, and length. * The air system may be charged from an outside air source not passing through the air dryer; outside air should pass through the air dryer if this provision is necessary. * The air dryer might not be purging; refer to Symptom #5. * Insufficient purge time could be due to excessive system leakage; check the causes and remedies for Symptom #1. * Excessive air usage or an incompatible air dryer could be the issue; see Appendix A, Tab...
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Jennifer PerryNov 6, 2025
Why is the safety valve on my BENDIX Dehumidifier popping off?
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  lauren27Nov 6, 2025
  The safety valve on your BENDIX Dehumidifier might be popping off due to several reasons: * There could be a restriction between the air dryer and the supply reservoir. Check for kinked tubing or restricted fittings. * The air dryer safety valve itself may be malfunctioning and needs replacement after verifying the relief pressure against the manufacturer's specifications. * The desiccant cartridge might require maintenance; refer to Appendix A Table A and column 3 to check the compressor for excessive oil or correct installation. Replace the desiccant cartridge if needed. * A defective discharge check valve in the end cover of the AD-9™ air dryer might be malfunctioning. Test it and repair or replace it. * Excessive pressure pulsations from the compressor can also cause this i...

BENDIX AD-9 AIR DRYER Specifications

General

Type	Air Dryer
Model	AD-9
Manufacturer	Bendix
Maximum Operating Pressure	150 PSI
Inlet Port	1/2" NPT
Outlet Port	1/2" NPT
Reservoir Volume	Not Applicable
Function	Removes moisture and contaminants from compressed air