1999 Other GMC Models Heater Core

  • 1999 GMC

Heater problem
1999 Other GMC Models V8 Four Wheel Drive Automatic 99,000 miles

How do you change the heater core on a 99 GMC K2500 4x4 5.7L? I know where it is located, but don't know how to remove it. Any info would help, Thanks

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Friday, November 14th, 2008 AT 7:41 AM

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Removal & Installation ("C" & "K" Series)
Disable air bag system. See AIR BAG SYSTEM SAFETY article in GENERAL INFORMATION. Disconnect negative battery cable. Remove glove box by squeezing sides together. Remove 2 instrument panel retaining bolts from glove box opening. Remove center floor duct. Remove center support bolt. Remove Electronic Control Module (ECM) and tray. Remove both kick panels. Remove blower motor cover and blower motor.
Remove driver's lower instrument panel cover and knee bolster. Lower steering column. Remove instrument panel left and right pivot bolts located at lower corners of instrument panel. Remove 3 screws from defrost vent, near windshield. Disconnect any connectors and tilt instrument panel back far enough to access heater case. Remove coolant recovery reservoir from engine compartment. Drain engine coolant. Disconnect heater hoses at core. Remove bolts and nuts from engine compartment attaching heater case to vehicle. Remove heater case.
Remove 7 screws attaching heater case cover plate. Remove screws and bracket attaching core to case. See Fig. 6 . Remove heater core. To install, reverse removal procedure. Replace any seals. Fill cooling system. Start engine and check for leaks.


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Monday, February 16th, 2009 AT 10:41 PM

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