BENDIX AD-IP INTEGRAL PURGE AIR DRYER

Questions and Answers

J
Johnny HallAug 9, 2025
What to do if my BENDIX AD-IP INTEGRAL PURGE AIR DRYER won't build system air pressure?
- B
  Bernard HarveyAug 9, 2025
  If your BENDIX Dehumidifier isn't building system air pressure, first check that the inlet and outlet air connections aren't reversed; connect the compressor discharge to the air dryer supply port. Reconnect lines properly. Also, inspect the check valve between the air dryer and the first reservoir for proper operation and repair or replace it if necessary. A kinked or blocked discharge line can also be the culprit; check to determine if air passes through discharge line. Check for kinks, bends, excessive carbon deposits, or ice blockage. Excessive bends in the discharge line, which can collect water and freeze, may also be a cause; ensure the discharge line slopes constantly from the compressor to the air dryer with as few bends as possible. Refer to Symptom 4, Causes E & F.
P
Peter PaulAug 14, 2025
Why is my BENDIX AD-IP INTEGRAL PURGE AIR DRYER Dehumidifier constantly cycling or purging?
- T
  Thomas GreenAug 14, 2025
  The BENDIX Dehumidifier might be constantly cycling or purging due to excessive system leakage. If gauges show leakage, test for excessive service brake system leakage. Allowable leakage: Single vehicle - 1 psi/minute either service reservoir. Tractor trailer - 3 psi/minute either service reservoir. Repair and retest as required. Another cause might be a Holset “E” type compressor. Test the Holset E Compressor unloader system with feedback line and check valve for proper operation. Make certain Holset ECON is not in use with the drop-in version of the air dryer, if so, remove and retest. When installing a Bendix Drop-In air dryer in a system equipped with a Holset E or QE compressor, remove the Holset ECON valve along with its feedback and governor control line.
M
Madison OrtegaAug 25, 2025
What to do if BENDIX AD-IP INTEGRAL PURGE AIR DRYER Dehumidifier does not purge or exhaust air?
- C
  Christopher MendezAug 25, 2025
  If the BENDIX Dehumidifier does not purge or exhaust air, inspect the purge control line from the governor UNL (unloader) port to the control port of the air dryer for missing, broken, kinked, frozen, plugged or disconnected line. Test to determine if air flows through purge control line when compressor unloaded. Check for undrilled fittings. (See Symptom #4, Remedy C.) If air reaches the purge valve (Remedy A above), repair purge valve. See Causes, B, E, G for Symptom #4.
U
ujonesOct 29, 2025
What to do if there is constant exhaust of air at BENDIX AD-IP INTEGRAL PURGE AIR DRYER Dehumidifier purge valve exhaust?
- K
  Kristin ParkerOct 29, 2025
  If there's constant exhaust of air at the BENDIX Dehumidifier purge valve exhaust, it could be due to several reasons. First, the air dryer purge valve might be leaking excessively. Apply soap solution on purge valve exhaust, to test for excessive leakage. Refer to Technical Bulletin TCH-008-040. Repair purge valve as necessary. Second, the compressor might fail to unload, causing a sputtering or popping sound. Confirm failure to unload by increasing & decreasing engine RPM and noting change in the rate of leakage and intensity of accompanying leakage sound. Repair/replace compressor unloaders. The purge control line might be connected to the reservoir or exhaust port of the governor, it must be connected to the unloader port of governor. The purge valve might be frozen open due to a malfu...
H
heatherfarleyNov 3, 2025
What to do if my BENDIX AD-IP INTEGRAL PURGE AIR DRYER Dehumidifier has water and/or oil in the supply or service reservoir?
- B
  Bill SmithNov 3, 2025
  If you find water and/or oil in the supply or service reservoir of your BENDIX Dehumidifier, it could be due to several factors. It may be caused by improper discharge line length or material, exceeding the maximum air dryer inlet temperature, refer to section entitled Connecting the Air Lines as well as Appendix A, Table A columns 1 & 2 then check line size and length. Another cause could be the air system being charged from an outside air source that isn't passing through the air dryer; if a fill provision is needed, ensure outside air passes through the dryer, but minimize this practice. The air dryer not purging can also cause the issue. Purge time insufficient due to excessive system leakage can also cause the issue. Check causes and remedies for Symptom #1. Excessive air usage, where...
R
reyesdavidNov 18, 2025
What to do if BENDIX Dehumidifier safety valve keeps popping off?
- K
  Kevin DiazNov 18, 2025
  If the safety valve on your BENDIX Dehumidifier is popping off, it could be due to a restriction between the air dryer and the supply reservoir. Inspect for kinked tubing or hose, or check for undrilled or restricted hose or tubing fittings, and repair or replace them as needed. It may also be caused by air dryer safety valve malfunction, verify relief pressure is at vehicle or component manufacturer specifications. Replace if malfunctioning. Desiccant cartridge maintenance may also be required. Check compressor for excessive oil passing and/or correct compressor installation. Repair or replace as necessary. Replace desiccant cartridge. Malfunctioning discharge check valve in end cover of the AD-IP™ air dryer may also cause this problem. Test to determine if air is passing through check va...