GM S-Series Pick-ups and SUV's 1994-1999 Repair Guide

Engine Oil Cooler & Adapter


Some of the vehicles covered by this guide may be equipped with an original equipment oil cooler and adapter. On these vehicles the oil cooler is usually built into the left side of the radiator, while the adapter is mounted between the engine block and oil filter. The following procedure may be used to service these parts. But, your vehicle might instead be equipped with an aftermarket cooler and adapter. Although the adapter for most aftermarket kits will be removed and installed in the same manner as the OEM adapter, aftermarket coolers are usually not integral with the radiator. If equipped, aftermarket coolers are usually separate radiator units mounted near the truck's radiator. When dealing with an aftermarket unit, follow the manufacturer's instructions.


See Figures 1 and 2

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Fig. Fig. 1: View of the engine oil cooler and line routing-2WD models

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Fig. Fig. 2: View of the engine oil cooler and lines-4WD models

  1. Disconnect the negative battery cable.
  3. Remove the oil filter from the adapter.
  5. Disconnect the oil cooler lines from the oil cooler adapter.
  7. Unfasten oil cooler adapter retaining bolt, then remove the adapter from the engine block.
  9. If necessary, remove the radiator from the vehicle to service or replace the engine oil cooler tank. The radiator may be taken to a repair shop if the tank is to be replaced.

To install:
  1. If removed, install the radiator to the vehicle. For details, please refer to the procedure earlier in this section.
  3. Install the oil cooler adapter to the engine block and secure using the retaining b