GM Service Manual Online
For 1990-2009 cars only

Coolant Bypass Hose Replacement LH2

Removal Procedure

Tools Required

J 38185 Hose Clamp Pliers

    Caution: To avoid being burned, do not remove the radiator cap or surge tank cap while the engine is hot. The cooling system will release scalding fluid and steam under pressure if radiator cap or surge tank cap is removed while the engine and radiator are still hot.

  1. Drain the cooling system. Refer to Cooling System Draining and Filling .
  2. Remove the surge tank outlet hose assembly. Refer to Radiator Surge Tank Outlet Hose/Pipe Replacement .

  3. Object Number: 1258140  Size: SH
  4. Disengage tension on the upper coolant bypass hose clamp using the J 38185 .
  5. Disengage tension on the lower coolant bypass hose clamp using the J 38185 .
  6. Remove the coolant bypass hose from the vehicle.

Installation Procedure

    Important: Lubricate the inside diameters of the hose with clean coolant prior to installation.

  1. Install the coolant bypass hose to the vehicle.

  2. Object Number: 1258140  Size: SH
  3. Position and engage tension on the lower coolant bypass hose clamp using the J 38185 .
  4. Position and engage tension on the upper coolant bypass hose clamp using the J 38185 .
  5. Install the surge tank outlet hose assembly. Refer to Radiator Surge Tank Outlet Hose/Pipe Replacement .
  6. Fill the cooling system. Refer to Cooling System Draining and Filling .

Coolant Bypass Hose Replacement LC3

Removal Procedure


    Object Number: 1688441  Size: SH
  1. Drain the cooling system. Refer to Cooling System Draining and Filling .
  2. Remove the water outlet housing. Refer to Water Outlet Housing Replacement .

  3. Object Number: 1688439  Size: SH
  4. Compress the clamps (1) as shown, and remove the bypass hose from the water outlet housing.

Installation Procedure


    Object Number: 1688439  Size: SH
  1. Install the bypass hose and clamps (1) to the water outlet housing.

  2. Object Number: 1688441  Size: SH
  3. Install the water outlet housing. Refer to Water Outlet Housing Replacement.
  4. Fill the cooling system. Refer to Cooling System Draining and Filling.
  5. Check the cooling system for leaks.