How to Remove a Heater Core From a 2000 Jimmyby Russell Wood
The heater core in a 2000 GMC Jimmy is responsible for creating the heat that flows through the vents when the heater is turned on. It does this by using the coolant from the radiator to heat a coil that then provides heat to the blower motor. When the heater core fails, it can leak, causing coolant to spill onto the ground and, in some cases, into the cabin. To fix the problem, start by removing the heater core.
Allow the Jimmy to cool for at least three hours before working on the heater core. Open the hood. Locate the heater core, which is inside a large black box on the passenger side of the engine compartment at the firewall. Put the drain pan underneath the heater core and remove the hose clamps holding the radiator lines to the heater core using the pliers or the flat-head screwdriver, depending on the type of hose clamps.
Unbolt the heater core casing and HVAC module casing--the component located directly to the right of the heater core housing that has the aluminum air-conditioning lines running into it--using the 3/8-inch ratchet and socket. Do this until you can see the heater core on the inside of the casing.
Pull the heater core out of the casing with both of your hands, making sure not to spill coolant on yourself in the process.