Repairing or replacing the heater core on a Jeep Cherokee is a complicated procedure, and might be best left to a professional. However, it can be done with basic hand tools, provided the mechanic is experienced and comfortable with tearing apart large chunks of his Jeep's interior. This is not a job for beginners and requires disposing of toxic air conditioning coolant.
Disconnect the battery and remove it. Drain the cooling system. Turn the wheel in a straight-ahead position. Wait for two minutes for the airbag system capacitor to discharge before attempting to work on any steering components.
Remove the steering column and knee blocker's four screws with a Phillips head screwdriver. Remove the steering column.
Remove the A-pillar trim with a Phillips head screwdriver. Remove the upper cover from instrument panel.
Remove the three panel-to-hinge screws with a medium Phillips head screwdriver, and remove the four panel-to-dash nuts.
Disconnect air conditioning lines from the condenser with a 5/8 line wrench and cap the openings. Disconnect heater core tubes with a flat-head screwdriver.
Disconnect vacuum fittings from the T-fitting near the heater core.
Evacuate air conditioning lines and recover refrigerant. Many cities offer a traveling refrigerant recovery service. The best way to find one is to contact your local new car dealership, since many of these companies do not advertise.
Under the hood, remove the five heater/air conditioning housing-chassis-nuts with a 1/2" deep well socket.
Remove the cowl plenum and drain tube from core from the AC housing stud, located behind the engine cylinder head.
Remove all ducting from the AC plenum housing with a gentle rocking motion, starting with the floor tube.
On the passenger side, remove the AC housing-to-plenum bracket screw with a Phillips head screwdriver.
Pull the AC housing down far enough to clear the vents, and backward to slide it from the mounting studs and remove the entire assembly from vehicle..
On the now-divorced AC assembly, remove the upper case, and lift the heater core from the lower case,
Replace the heater core with a new unit.
Reverse your steps to reassemble.
Re-fill refrigerant with store-bought kit. Make purchase a kit with the proper adapters for your system.
Re-install and re-connect battery.
Refill cooling system and check for leaks.
Run vehicle and check system for leaks.
