GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1998 🢒 GMC C Pickup - 2WD (CNG) 🢒 Engine 🢒 Engine Cooling 🢒 High Pressure Regulator Coolant Outlet Hose Replacement

Removal Procedure

    Object Number: 318489 Size: SH

    Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

  1. Drain the cooling system. Refer to Draining and Filling Cooling System in Engine Cooling in the C/K Truck Service Manual.
  2. Remove the air cleaner assembly. Refer to Air Cleaner Assembly Replacement in Engine Controls - 5.0, 5.7L in the C/K Truck Service Manual.
  3. Remove the tie wraps.
  4. Remove the nuts from the hose clamps.
  5. Remove the hose clamps from the hoses.

    6. Object Number: 318478 Size: SH
  6. Disconnect the outlet hose (1) from the Y-fitting.

    7. Object Number: 318500 Size: SH
  7. Disconnect the outlet hose (1) from the HPR.
  8. Remove the HPR outlet hose from the vehicle.

Installation Procedure

    Object Number: 318500 Size: SH
  1. Install the HPR outlet hose into the vehicle.
  2. Connect the outlet hose (1) to the HPR.

    3. Object Number: 318478 Size: SH
  3. Connect the outlet hose (1) to the Y-fitting.

    4. Object Number: 318489 Size: SH
  4. Install the hose clamps to the hoses.

    5. 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.

  5. Install the nuts to the hose clamps.

    6. Tighten
    Tighten the hose clamp nuts to 1.7 N·m (15 lb in).

  6. Install the tie wraps.
  7. Install the air cleaner assembly. Refer to Air Cleaner Assembly Replacement in Engine Controls - 5.0, 5.7L in the C/K Truck Service Manual.
  8. Fill the cooling system. Refer to Draining and Filling Cooling System in Engine Cooling in the C/K Truck Service Manual.
  9. Start the engine. Check for coolant leaks when the engine reaches the normal operating temperature.