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SERIES 55 OIL COOLER

In order for the engine to function satisfactorily, the lubricating oil must be kept within proper temperature limits. If the oil is too cold, it will not flow freely. If the oil is too hot, it cannot support the bearing loads, and it cannot carry away enough heat. As a consequence, oil pressure may drop below acceptable limits, and oil consumption may become excessive. ‪

While performing its lubricating and cooling functions, the oil absorbs a considerable amount of heat, and this heat must be dissipated by an oil cooler. To ensure continued engine lubrication if the oil filter becomes plugged, a bypass passage directs oil around the filter directly to the oil gallery in the cylinder block. Cooling water circulates through the oil cooler housing and around the oil cooler core. See Figure 25327 . ‪

1.Oil Filter Adaptor ‪

2.Oil Cooler Housing ‪

Oil Cooler Housing Assembly

Replacement of Oil Cooler

Repair of this component is not authorized at this time. ‪

To determine if repair is possible or replacement is necessary, perform the following procedure. See Figure 21754 . ‪

Repair or Replacement of Oil Cooler Flowchart

Removal and Cleaning of Oil Cooler

Pre-cleaning is not necessary. ‪

Remove the oil cooler core and housing as follow: See Figure 25325 . ‪

1.Oil Cooler Housing ‪

7.Oil Cooler Element ‪

2.Oil Cooler Housing Gasket ‪

8.Oil Cooler Element Bolt (8) ‪

3.Cylinder Block ‪

9.Oil Filter Adaptor ‪

4.Adaptor Plate Bolt, Long Bolts (4) ‪

10.Oil Filter Adaptor Bolts (6) ‪

5.Adaptor Plate Bolt, Short Bolts (4) ‪

11.O-ring Seal (4) ‪

6.Oil Cooler Element Gasket ‪

Removal of Oil Cooler Assembly

  1. Drain the cooling system by removing the pipe plug on the oil cooler housing assembly.
  2. Remove the bolts that attach the oil filter adaptor to the oil cooler housing.
  3. Remove the bolts that attach the core to the cooler housing.
  4. Remove the oil cooler housing and gasket from the cylinder block.

    Note: Clean all traces of gasket material off of the cylinder block.

  5. Use a gasket scraper or chisel and a fiber mallet or plastic hammer to separate the oil cooler core and housing.
  6. Remove all traces of gasket material from the oil cooler and housing.

Clean the oil cooler core prior to inspection as follows: ‪

  1. Remove the core from the oil cooler.

    To avoid injury from improper use of chemicals, follow the chemical manufacturer's usage, handling, and disposal instructions. Observe all manufacturer's cautions.

    NOTICE:

    Do not clean the oil cooler when an engine failure releases metal particles into the lubricating oil. The oil cooler core must be replaced. If it is not replaced, severe engine damage may result. ‪

  2. Circulate Tech Solv 340 through the core passages with a force pump to remove the carbon and sludge.
  3. Clean the core before the sludge hardens.
  4. Visually check the oil passages. If the oil passages are badly clogged, circulate an or alkaline solution through the core, and thoroughly flush it with clean hot, water.
  5. Clean the water side (outside) of the core:

    To avoid injury from improper use of chemicals, follow the chemical manufacturer's usage, handling, and disposal instructions. Observe all manufacturer's cautions.

    1. Mix the following solutions: Add 1.1 kg (.5 lb) of oxalic acid to each 9.5 L (2.5 gal) of solution composed of one-third muriatic acid and two-thirds water.
    2. Immerse the core in the solution.
    3. Watch the process carefully. When bubbling stops (this usually takes from 30 to 60 seconds), remove the core from the cleaning solution.
    4. Thoroughly flush it with clean, hot water.
    5. Dip the core in light oil.
Inspection of Oil Cooler Core

Inspect oil cooler core as follows: ‪

  1. Using the oil cooler core as a template, make a suitable plate and rubber gasket.
  2. Drill and tap the plate prior to mounting to permit an air hose fitting to be attached to the core. See Figure 25328 .

    1.Oil Cooler Core ‪

    3.Air Hose ‪

    2.Plate ‪

    4.Gasket ‪

    Preparing Oil Cooler Core for Pressure Test

  3. Attach plate to the flanged side of the oil cooler core using suitable nuts, washers, and bolts.

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

  4. Attach an air hose to the air hose fitting.
  5. Regulate air pressure to 517-690 kPa (75-100 lb/in.2 ), and submerge the oil cooler and plate assembly in a container of water heated to 82 C (180 F).
    1. Water bubbles indicate leaks. If leaks are indicated, replace the core.
  6. After the pressure check is completed, remove the plate and air hose from the cooler core.

    To avoid injury from flying debris when using compressed air, wear adequate eye protection (face shield or safety goggles) and do not exceed 40 psi (276 kPa) air pressure.

  7. Dry the core with compressed air.

    Note: Whenever a leaky oil cooler core causes engine contamination, the engine must be immediately flushed to avoid corrosion of its internal components.

Installation of Oil Cooler

Install the oil cooler as follows: See Figure 25325 . ‪

1.Oil Cooler Housing ‪

7.Oil Cooler Element ‪

2.Oil Cooler Housing Gasket ‪

8.Oil Cooler Element Bolt (8) ‪

3.Cylinder Block ‪

9.Oil Filter Adaptor ‪

4.Adaptor Plate Bolt, Long Bolts (4) ‪

10.Oil Filter Adaptor Bolts (6) ‪

5.Adaptor Plate Bolt, Short Bolts (4) ‪

11.O-ring Seal (4) ‪

6.Oil Cooler Element Gasket ‪

Installation of Oil Cooler Assembly

  1. Install the new O-rings in the oil filter adaptor counterbores.
  2. Install a new gasket on the face of the core.
  3. Install the core to the housing, and install the assembly on the cylinder block with new oil cooler housing gasket. See Figure 25838 .

    Torque Sequence for Oil Cooler Assembly Components

  4. Align the oil filter adaptor with the oil cooler housing assembly. Install the M10 bolts and tighten them to 58-73 N m (43-54 lb ft) torque in the proper sequence. Install the M8 bolts and tighten them to 30-38 N m (22-28 lb ft) torque in the proper sequence. See Figure 26823 .

    Oil Filter Adaptor Bolt Torque Sequence

  5. Install the pipe plug on the bottom of the oil cooler housing assembly.
  6. Tighten the plug to 28-33 N m (19-24 lb ft).
  7. Fill the cooling system. Refer to section . Refer to section
  8. Fill the lubricating system. Refer to section .
  9. refer to section for verification of proper oil cooler installation.