Haldex PURest Information in this section is provided by Haldex and is used with permission.

rv mm 42.03.000

Note: Desiccant change intervals may vary from vehicle to vehicle. Typical desiccant cartridge life is three years. However, if experience has shown that extended or shortened life has resulted on a particular installation, then the interval can be increased or decreased accordingly.

Note: The PURest cartridge contains both the desiccant and filter in one piece.

  1. Park the vehicle on a level surface, shut down the engine, and set the parking brake. Chock the tires.
  2. Remove the four mounting bolts and discard. See Fig.. Lift the canister about 1/2 inch and remove.

    1. O-ring

    2. Cartridge

    3. Mounting Bolts

    Fig. 1, PURest Air Dryer Assembly

  3. Place the assembly upside-down as shown in Fig.. Press the cartridge down to compress the rubber spring then rotate counterclockwise 45 degrees to release the cartridge. The cartridge itself contains no hazardous material, but there may be a small amount of oil from the compressor.

    • Canister/cartridge assembly shown upside-down.

    • Rotate the cartridge counterclockwise 45 degrees to release it from the canister.

    Fig. 2, Releasing the Cartridge

  4. Clean the inside of the canister and aluminum housing.
  5. Remove the cartridge O-ring and discard.
  6. Remove the new cartridge from the kit and make certain the rubber spring is attached. See Fig..

    Fig. 3, New Cartridge with Rubber Spring

  7. Install the new cartridge into the canister. Align the slots on the cartridge with the dimplets inside the canister. Press the cartridge into the canister and rotate clockwise 45 degrees to engage the cartridge, as shown in Fig..

    • Install the new cartridge into the canister.

    • Press the cartridge into the canister and rotate clockwise 45 degrees to engage the cartridge.

    Fig. 4, Cartridge Rotation and Engagement

  8. Place a new O-ring on the aluminum housing.
  9. Place the cartridge assembly on the air dryer housing and install four new mounting bolts. Use an alternating diagonal pattern and tighten the bolts 35 to 40 lbf·ft (47 to 54 N·m).
  10. Before placing the vehicle in service, perform the test below.
    1. Start the engine and build air pressure to 100 psi (690 kPa) and shut-off the engine.
    2. Check for air leaks at the inlet, outlet, and canister assembly. Correct any leakage problem.
    3. Restart the engine and build-up pressure to cut-out pressure. At cut-out pressure, the air dryer purge valve opens and immediately expels a large volume of air, followed by a slow flow of air lasting approximately 30 seconds.
Note:
Parent topic: Replacing the Air Dryer Desiccant and Coalescent Filter
Document Number: 0000120670
Manual Publication Date: 2024-05-23
Topic Publication Date: 2024-11-13