Monday, February 28, 2011

how do you replace the heater core on a 1999 buick century?

Removal

  • Disconnect the negative battery cable by loosening the post with a socket wrench. Drain the coolant from the engine by opening the drain on the bottom of the radiator and the two drains above the oil pan with a wrench or pliers. Make sure the radiator cap is off while you do this to ensure the coolant drains properly. Collect the coolant in a bucket or tub for re-use.

  • Remove the lower instrument sound insulation panel from the below the glove box on the passenger side by loosening its clips and screws with pliers and a screwdriver. Loosen and remove the clips on the heater floor outlet duct and remove the duct.

  • Remove the screws and clips holding the heater core cover in place with a screwdriver and pliers and remove the cover.

  • Unbolt the four heater core mounting bolts with a socket wrench and remove the bolts and retaining straps. Disconnect the inlet and outlet hoses from inside the engine compartment where they connect to the heater core. Remove the heater core being careful not to spill any residual coolant as you pull it from under the dash.

  • Put the new or rebuilt heater core in place under the dash and install the retaining straps with the mounting bolts. Tighten the bolts with a socket wrench. Put the cover in place and attach its clips and screws.

  • Put the heater duct back in place and fasten its clips and screws. Install the lower instrument panel sound insulator and reconnect the inlet and outlet hoses from inside the engine compartment.

  • Close and tighten the radiator drains with pliers or socket wrench. Pour the coolant into the radiator until it reaches the base of the radiator filler neck. Pour coolant into the overflow tank to the "Full" mark.

  • Reconnect the battery and start the engine with the radiator cap off. The engine running will draw coolant through the cooling system and expel air from the system. As the level falls from the top of the radiator pour more fluid in until it stays steady at the base of the radiator filler neck. Put the radiator cap in place and turn it clockwise until it is firmly in place, making sure the arrow on the cap points towards the overflow tank.

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    Removing the Heater Core

    • Lift the hood and prop it open. Makes sure the engine is cold. Disconnect the negative battery cable with a socket wrench or box wrench. Avoid using open-end wrenches on the battery terminals, as they tend to strip the bolt heads.

    • Place a drain pan under the radiator. Open the radiator cap. Open the radiator drain on the bottom of the radiator and the two coolant drains near the oil pan. You can reuse the coolant unless it appears cloudy and contaminated. Close all three drain openings once all the coolant has drained from the syste

    • Disconnect the inlet and outlet hoses of the heater core inside the engine compartment using a socket wrench. Be prepared to catch or wipe up any coolant that drips from these hoses. Drain the coolant from inside the heater cor

    • Unscrew and remove the lower instrument panel sound insulator from below the dashboard on the passenger side. Use a socket or screwdriver to loosen and remove the screws on the heater floor outlet. Remove the clips and take out the duct.

    • Loosen and remove the screws holding the heater core cover in place. Remove the cover.

    • Remove the retaining bolts holding the heater core in place. Remove the heater core.

    Installing the Heater Core

    • Position the replacement heater core and secure the retaining bolts. Put the cover back on the heater core and reattach the screws and clips.

    • Reinstall the floor outlet duct with its screws and clips, followed by the lower instrument panel sound insulator.

    • Reconnect the inlet and outlet hoses to the heater core In the engine compartment.

    Refilling the Cooling System

    • Tighten all of the drains. Fill the radiator up to the base of the radiator neck with antifreeze, reusing the old coolant if it's clean. Fill the coolant overflow tank up to the "FILL" mark.

    • Reconnect the negative cable on the battery and start the engine, making sure you leave the radiator cap off. With the engine idling, look into the radiator and notice that the coolant level has dropped. Add coolant until the level is back up to the base of the radiator neck. Add coolant to the "FILL" mark on the overflow tank. Put the radiator cap on, making sure the arrow on it points to the overflow tan

    • Squeeze the large return hose leading to the top of the radiator with the engine still running. The hose should begin to feel hot, indicating that the thermostat has opened and is functioning properly.

    • Check for leaks in the cooling system.


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