Instructions are from the FSM with my notes.
HEATER CORE AND HOUSING REMOVAL
WARNING: HOT ENGINE COOLANT CAN CAUSE
SEVERE BURNS. DO NOT OPEN THE RADIATOR
DRAIN COCK WHEN THE COOLING SYSTEM IS
HOT AND PRESSURIZED. ALLOW THE COOLANT
TO DECREASE TO ROOM TEMPERATURE BEFORE
STARTING REPAIR OPERATIONS.
(1) Drain approximately 1.9 liters (2 qts) of coolant from the radiator. Drain the coolant into a clean container.
- I didn't bother doing this. If you're quick you can pull the hose off and raise it up so it doesn't drain out. Then wedge it upright or clamp it off with some Vice-grips.(2) Disconnect the heater hoses.
(3) Disconnect the vent door cables.
- Remove the phillips that holds the lower duct to the main housing. It comes off separately. Then reach in and pinch the clips that hold the cable to the housing.(4) Disconnect the blower motor wire.
- It's on top of the vent housing and clips into the dash harness near the left speaker.(5) Disconnect the defroster duct. -You can just pull it up off the main housing.
(5b) I highly recommend removing the battery and taking the battery tray out. There are 6-7 bolts holding it on. 2 bolts on the support brackets from the firewall, 2 that hold the tray to the firewall, One that holds the tray to the lower support bracket and 2 that connect the PDC bracket to the fender. Yes, the PDC will have to move. You can unclip it and carefully push it towards the engine compartment and it will come off.(6) Remove the nuts that attach the heater housing studs to the engine compartment side of the dash panel.
- There are 4. 3 Under the Battery Tray and one behind #4 Cylinder fuel injector. IIRC everything is 15mm.(7) Remove the heater housing assembly by tilting it downward, to disengage it from the defroster duct.
Pull it rearward and out from under the instrument panel.
(
Remove the heater hosing cover from the housing.
(9) Remove the heater core from the housing.
INSTALLATION
(1) Install the heater core in the housing and install the cover on the housing.
(2) Position the heater housing on the dash panel.
Be sure the housing studs all extend through the dash panel.
(3) Install the seals on the heater core outlet and
inlet tubes and over the blower motor housing.
(4) Install the attaching nuts on the housing studs.
CAUTION: DO NOT over tighten the attaching nuts. The housing could become distorted causing air leaks and improper heater door operation. Tighten the nuts alternately and evenly until 2 stud threads are visible beyond each nut.
(5) Connect the defroster duct to the housing.
(6) Connect the blower motor wire.
(7) Connect the vent door control cables. -If any of the clips that hold it to the housing broke, use RTV and hold it in place with some tape till it dries.
(
Connect the heater hoses.
(9) Fill and bleed the cooling system.
(10) Check system operation.
The first signs of a bad heater core. Steam from the defroster and the sweet smell of the Antifreeze.
It will begin to leak from the lowest point in the housing.
And them some...
Once the Battery Tray is removed you can get down to business.
Notice the small rubber elbow. That's the drain for the vent.
There are three sets of cables. Each has a plastic retainer clip. Be careful removing these. Too much force and they will break off. BTDT. There are small clips at the end of the cables that hold it to the metal rods. use needle nose pliers to wiggle them off.
Once the duct is out you can remove the small screws that hold the housing together. There are two screws that hold the heater core in place. You can see the two on either side of the label.
Be careful not to lose any of the plastic bushings or clips that hold the doors on.
The new core is different then the old one. There are no mounting screws. This isn't a problem as it just sort of wedges itself in there. You might try to reuse the foam on the old heater core but chances are it's not going to come off in one piece. I used some Camper Shell foam I had. It doesn't need much.
