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MBE 4000 AIR COMPRESSOR

The air compressor, with a power-steering pump attached, is driven by a gear on the camshaft. Perform the following procedures for removal and installation of the air compressor. ‪

Air Compressor Removal

Remove the air compressor as follows: ‪

HOT COOLANT

To avoid scalding from the expulsion of hot coolant, never remove the cooling system pressure cap while the engine is at operating temperature. Wear adequate protective clothing (face shield, rubber gloves, apron, and boots). Remove the cap slowly to relieve pressure.

  1. Drain the coolant.
  2. Remove the two bolts attaching the power steering pump to the air compressor. See Figure 42325 .

    1. Mounting Bolt ‪

    4. Cross Plate ‪

    2. Power Steering Pump ‪

    5. Air Compressor ‪

    3. O-ring ‪

    6. Hydraulic Lines ‪

    Power Steering Pump Removal

    Note: Do not remove the power steering lines. Tie up the lines and move the pump out of the way.

  3. Remove the cross plate between the compressor and the power steering pump.
  4. Remove the three air lines. See Figure 42326 .

    1. Discharge Air Line ‪

    5. Intake Air Line ‪

    2. O-ring ‪

    6. Hose Clamp ‪

    3. 90 Elbow ‪

    7. Unloader Air Line ‪

    4. Air Compressor ‪

    Air Line Attachments

    PERSONAL INJURY

    To avoid injury from the sudden release of a high-pressure hose connection, wear a face shield or goggles.

    1. Remove the discharge (compressed air) line and the 90 elbow. Check inside the discharge line for carbon deposits. If deposits are found, replace the discharge line.

      Note: The 90 elbow on the discharge line must be removed to allow removal of the engine trim cover.

    2. Remove the unloader line. Check the fittings for damage and replace if necessary.
    3. Loosen the hose clamp and remove the intake (suction) air line.
  5. Remove the engine trim cover.

    Note: The bottom of the engine trim cover overhangs the coolant delivery line fasteners, making them difficult to remove.

  6. Remove the coolant delivery line and coolant return line. Discard the seal rings. See Figure 42327 .

    1. Hollow-Core Banjo Bolt ‪

    4. Air Compressor ‪

    2. Seal Ring ‪

    5. Coolant Return Line ‪

    3. Coolant Delivery Line ‪

    Air Compressor Coolant Lines

  7. Remove the four mounting bolts attaching the air compressor to the crankcase. See Figure 42328 .

    1. Inboard Upper Mounting Bolt ‪

    5. Outboard Upper Mounting Bolt ‪

    2. Air Compressor ‪

    6. Outboard Lower Mounting Bolt ‪

    3. Cylinder Block ‪

    7. Inboard Lower Mounting Bolt ‪

    4. Flywheel Housing ‪

    Air Compressor Mounting

    Note: The mounting bolts are of different lengths. The outboard upper mounting bolt is removed from the rear.

  8. Slide the drive gear away from the flywheel. Catch any oil that runs out and dispose of it properly.
Air Compressor Inspection

Inspect the air compressor as follows: ‪

  1. Inspect the O-rings on the fittings at the air system ports and replace if necessary. If the O-rings are damaged, replace the fittings also.
  2. Replace the O-ring between the power steering pump and the air compressor.
  3. Install the locking device (J 46177 or 457 589 03 63 00) on the driveshaft end of the air compressor. This locks the driveshaft to allow removal of the drive nut.
  4. Remove the drive gear from the air compressor.
    1. Place the air compressor and locking device (J 46177 or 457 589 03 63 00) in a vise. Make sure the locking device is tightly secured and cannot slip or slide out of the vise.
    2. Using an impact wrench, remove the drive nut from the drive gear.
    3. Remove the locking device (J 46177 or 457 589 03 63 00) from the air compressor and the vise.
    4. Remove the drive gear from the air compressor with a gear puller, if necessary.
    5. Discard the O-ring on the driveshaft end of the air compressor.
  5. Inspect the drive gear for worn or broken teeth, spalling, and corrosion. Replace the drive gear if necessary.
  6. Install the drive gear, drive nut, and a new O-ring on the driveshaft end of the air compressor. Tighten the drive nut 290 Nm (214 lbft). See Figure 42329 .

    1. Air Compressor ‪

    3. Drive Gear ‪

    2. O-ring ‪

    4. Drive Nut ‪

    Air Compressor Drive Gear Installation

  7. Release the air compressor from the vise.

Air Compressor Installation

Install the air compressor as follows: ‪

  1. Install the air compressor.
  2. Install the four air compressor mounting bolts. Tighten each bolt 60 Nm (44 lbft). See Figure 42328 .

    Note: Be sure the correct mounting bolt is mounted at each location. The outboard upper mounting bolt is installed from the rear.

  3. Install the two coolant lines.
    1. Replace the seal rings on the coolant lines.
    2. Install the coolant delivery line at the rear of the air compressor. Tighten the hollow-core banjo bolt 30 Nm (22 lbft).
    3. Install the coolant return line at the front of the air compressor. Tighten the hollow-core banjo bolt 30 Nm (22 lbft).
  4. Install the engine trim cover.
  5. Install the three air lines. See Figure 42326 .
    1. Install the discharge line and the 90 elbow. Make sure the O-ring is properly installed on the fitting.
    2. Install the uploader line. Make sure the O-ring is properly installed on the fitting.
    3. Tighten the fittings 80 Nm (60 lbft).
    4. Install the intake air line and tighten the hose clamp.
  6. Install the cross plate. Use grease to hold it in place while installing the power steering pump.
  7. Install the two bolts attaching the power steering pump to the air compressor. Tighten the bolts 40 Nm (30 lbft).
  8. Fill the radiator with coolant.