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HOMESERVICE MANUALSGMC1999FORWARD CONTROL 5.7 R, AUTOMATICREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 631 (ENGINE COOLING SYSTEM)REPAIR INSTRUCTIONSTHERMOSTAT REPLACEMENTREMOVAL PROCEDURE
1999 GMC Forward Control 5.7 R, Automatic

Removal Procedure

1999 GMC Forward Control 5.7 R, AutomaticSECTION Removal Procedure
WARNING: This page is about a different car, the 2003 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.

Important:  The water pump inlet and thermostat MUST be replaced as an assembly. The thermostat is not serviceable separately.

  1. Drain the cooling system. Refer to DRAINING AND FILLING COOLING SYSTEM .
  2. Reposition the outlet hose clamp at the water pump inlet.
  3. Remove the outlet hose from the water pump inlet.
    Fig 1: Removing Outlet Hose From Water Pump Inlet
    G01971769Courtesy of GENERAL MOTORS CORP.
  4. Remove the water pump inlet bolts.
  5. Remove the water pump inlet.
    Fig 2: Water Pump Inlet
    G01971770Courtesy of GENERAL MOTORS CORP.
  6. The O-ring seal is integral to the thermostat housing.
  7. Remove the thermostat housing.
    Fig 3: Thermostat Housing
    G01971771Courtesy of GENERAL MOTORS CORP.
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.