GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2003 🢒 Blazer - 4WD 🢒 Transmission/Transaxle 🢒 Automatic Transmission - 4L60-E/4L65-E 🢒 Transmission Fluid Cooler Hose/Pipe Replacement

Removal Procedure
  1. Remove the transmission oil cooler (TOC) lines from the radiator. Refer to Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection .

    2. On vehicles equipped with a 4.3L engine and 4WD, it may be necessary to gain access to the lower cooler line (2) through the right side wheel well opening.


    Object Number: 449301 Size: SH
  2. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  3. For vehicles equipped with a 2.2L engine, remove the nut securing the cooling line to the engine.

    4. Object Number: 449304 Size: SH
  4. For vehicles equipped with a 4.3L engine, remove the clip and stud securing the cooler line to the engine.
  5. Support the transmission with a transmission jack.

    6. Object Number: 680767 Size: SH
  6. Remove the exhaust crossover pipe and the transmission support assembly. Refer to Transmission Support Replacement in Frame and Underbody.
  7. Carefully lower the transmission to gain access to the cooler line fittings.
  8. Remove the TOC lines from the fittings on the transmission. Refer to Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection .

    9. If the vehicle is equipped with 4WD, it may be necessary to disconnect and temporarily relocate the transfer case vent hose to provide access to the fittings.

  9. Remove the TOC lines from the vehicle.

Installation Procedure
  1. Install the TOC lines to the vehicle.
  2. Install the TOC lines to the transmission. Refer to Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection
  3. Install the transfer case vent hose, if equipped.
  4. Raise the transmission into position.
  5. Install the exhaust crossover pipe and the transmission support assembly. Refer to Transmission Support Replacement in Frame and Underbody.
  6. Remove the transmission jack.

    7. Object Number: 449304 Size: SH

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  7. For vehicles equipped with a 4.3L engine, install the stud and clip securing the TOC line to the engine.

    8. Tighten
    Tighten the stud to 11 N·m (97 lb in).


    Object Number: 449301 Size: SH
  8. For vehicles equipped with a 2.2L engine, Install the nut securing the TOC lines to the engine.

    9. Tighten
    Tighten the nut to 11 N·m (97 lb in).

  9. Lower the vehicle.
  10. Install the TOC lines to the radiator. Refer to Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection .
  11. Fill the transmission to the proper level with DEXRON® III transmission fluid. Refer to Transmission Fluid Check .