Bendix AD9 Air Dryers

Bendix AD9 air dryer gm bus install

IF you need help, please send email for us..(Mail to :wabco@wabco.cn or wabco@wabco.cn)
Extended Maintenance Intervals

Bendix AD9 air dryers have a large capacity desiccant cartridge that allows for longer maintenance intervals. Air dryer rebuilds can be stretched to every 36 months when the AD-9 is installed on a typical over-the-road truck or tractor.
Easy To Service
Desiccant cartridge replacement is the only reason to ever completely disassemble the Bendix AD9 air dryer. The check valve, turbo cut-off valve, heater, and purge valve assembly can all be serviced without disassembling the air dryer.

Bendix ad9 air dryer cross reference: 065226, 107953, 107953X, 109685, 109685X, 65226, R1096859002783, 23880305, F0HZ2A131A, FOHZ2A131A, 4317715, 681410115, BW065225, 15665475, 26QE377, 26QE377P4, 26QE377P5, 26QE377P6, 745065225, 1673737C91, BX065225, ZAC065225, 1091606, 2FS82, 917352

Bendix Tech Talk: Air Compressor Diagnosis video:

This Bendix Tech Talk discusses the operation and maintenance of air compressors on commercial vehicle engines. Topics include spec’ing air compressors, remanufactured compressors, air management system troubleshooting, diagnostics, servicing, and technical support. The Bendix Tech Talk Series, presented by Bendix Commercial Vehicle Systems LLC at the annual Mid-America Trucking Show, aims to help educate drivers and fleets about topics such as advanced safety technologies, energy management solutions, CSA (Compliance, Safety, Accountability), and reduced stopping distance.

Bendix ad9 air dryer troubleshooting

This troubleshooting documentation was compiled from Bendix’s AD-9 troubleshooting Service Data Sheet. Download the data sheet for more detailed information.

      Dryer is constantly “cycling” or purging. Dryer purges frequently (every 4 minutes or less while vehicle is idling)

    • Excessive system leakage IMPORTANT: Note whether air pressure loss is shown on dash gauge(s). Pressure loss shown on gauges is caused by service brake system or component leakage. Pressure loss NOT SHOWN on gauges is caused by supply system or component leakage.
    • Leaking purge valve housing assembly and/or O-rings in air dryer end cover.
    • Holset® “E” type compressor – 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.

Water and/or Oil in Supply or Service Reservoir

    • Desiccant cartridge needs to be replaced
    • Improper discharge line length or line material – Maximum air dryer inlet temperature is exceeded.
    • Air system charged from outside air source (outside air not passing through air dryer)
    • Air dryer not purging
    • Purge (air exhaust) time insufficient due to excessive system leakage
    • Excessive air usage, duty cycle too high
    • Compressor malfunction – Passing oil
    • Air bypasses desiccant cartridge assembly – If vehicle has a Holset compressor, inspect feedback check valve.

Oil present at air dryer purge exhaust or cartridge during maintenanceA small amount of oil in these areas is normal.Safety valve on air dryer “popping off” or exhausting air

    • Restriction between air dryer and supply reservoir
    • Air dryer safety valve malfunction
    • Desiccant cartridge needs to be replaced
    • Governor malfunction. Missing or restricted governor control line installation

Constant exhaust of air at air dryer purge valve exhaust when air dryer is in Charge mode.

    • Air dryer purge valve leaking excessively
    • Compressor fails to unload (stop compressing air) and air dryer purge exhaust makes “sputtering” or “popping” sound
    • Purge control line connected to reservoir or exhaust port of governor. It must be connected to an unloader port on the governor.
    • Purge valve frozen open – malfunctioning heater and thermostat, wiring, blown fuse.
    • Excessive system leakage
    • Purge valve stays open – supply air leaks to control side – Replace purge valve and housing

Can not build system air pressure

    • Inlet and outlet air connections reversed
    • Check valve between air dryer and first reservoir malfunctioning
    • Kinked or blocked discharge line
    • Excessive bends in air compressor discharge line causing water to collect and freeze
    • Governor malfunction

Air dryer does not purge or exhaust air

    • Missing, broken, kinked, frozen, plugged or disconnected purge control line
    • Faulty air dryer purge valve
    • Air dryer safety valve malfunction

Desiccant material being expelled from air dryer purge valve exhaust

    • Air dryer not securely mounted. (Excessive vibration.)
    • Malfunctioning or saturated desiccant cartridge
    • Compressor passing excessive amount of oil
    • Desiccant cartridge not assembled properly to end cover. (Loose attachment)

“Pinging” noise excessive during compressor loaded cycle

    • Defective check valve assembly in air dryer end cover.
    • Leaking purge valve control piston o-ring.

Constant leaking of air at air dryer purge valve exhaust (non-charging mode.)

    • Defective check valve assembly in air dryer end cover.
    • Leaking purge valve control piston o-ring.

The air dryer purge piston cycles rapidly in the compressor unloaded (non-compressing) mode.

  • Compressor fails to “unload”

dissasembelind a Bendix air dryer service manual and inspection:

TESTING THE AD-9 Air Dryer

Before placing the vehicle in service, perform the following tests:

1.Close all reservoir drain cocks.
2.Build up system pressure to governor cut-out and note that the AD-9™ air dryer purges with an audible escape
of air.
3.“Fan” the service brakes to reduce system air pressure to governor cut-in. Note that the system once again builds
to full pressure and is followed by a purge at the AD-9 air dryer exhaust.
4. It is recommended that the following items be tested for leakage to assure that the AD-9™ air dryer will not cycle
excessively.

  • Total air system leakage (See Bendix publication BW-5057 “Air Brake Handbook”).
  •  Compressor unloader mechanism.
  •  Governor.
  • Drain cock and safety valve in first (supply) reservoir.
  • All air connections leading to and from the first (supply) reservoir.

REBUILDING THE AD9 AIR DRYER

GENERAL

If, after completing the routine operation and leakage tests,it has been determined that one or more components of the air dryer requires replacement or maintenance, refer to the following list to find the appropriate kit(s).

When rebuilding or replacing components of the air dryer use only genuine Bendix parts. For ease in servicing the
AD-9™ air dryer desiccant cartridge assembly, it is recommended that the air dryer be removed from the vehicle.

Maintenance kits available:

  • 5005037 Hard Seat Purge Valve Housing Maintenance Kit
  • 5005893 Soft Seat Purge Valve Housing Maintenance Kit
  • These kits contain the parts necessary to rebuild the air portion of the purge valve housing and do not include the heater and thermostat.
  • 107796 Remanufactured Desiccant Cartridge Replacement Kit
  • This kit contains the parts necessary to change the desiccant cartridge only.
  • 107794 Desiccant Cartridge Replacement Kit
  • This kit contains the parts necessary to change the desiccant cartridge only.
  • 107799 End Cover Check Valve Assembly Replacement 3/4 inch thread size.
  • 107800 End Cover Check Valve Assembly Replacement 1/2 inch thread size.
  • 800405 Service New Purge Valve Housing Assembly – Soft Seat (w/heater and thermo.) 12 volt system.
  • 5004341 Remanufactured Exchange Purge Valve Housing Assembly – Soft Seat (w/heater and thermo.) 12 volt system.
  • 5004479 Service New Purge Valve Housing Assembly – Hard Seat (w/heater and thermo.) 12 volt system.
  • 5004339 Service New Purge Valve Housing Assembly – DLU (w/heater and thermo.) 12 volt system.
  • 5004338 Service New Purge Valve Housing Assembly – Soft Seat (w/heater and thermo.) 24 volt system.
  • 5004342 Remanufactured Exchange Purge Valve Housing Assembly – Soft Seat (w/heater and thermo.) 24 volt system.
  • 5004480 Service New Valve Housing Assembly – Hard Seat (w/heater and thermo.) 24 volt system.
  • 5004340 Service New Purge Valve Housing Assembly – DLU (w/heater and thermo.) 24 volt system.
  • 107695 Complete Mounting Bracket Kit

This kit contains the upper and lower brackets aswell as the necessary hardware items to mount them.

GENERAL SAFETY GUIDELINES

WARNING! PLEASE READ AND FOLLOW THESE INSTRUCTIONS TO AVOID PERSONAL INJURY OR DEATH

IF you need help, please send email for us..(Mail to :wabco@wabco.cn or wabco@wabco.cn)