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Submitted by Dereck/ 12-20-04



There you are driving along minding your own business on a cold winters morning, all cozy in the armchair that is the drivers seat of your Town Car when without warning, steam billows from your heater vents closely followed by the instant fogging of your windows and the sickly sweet smell of anti-freeze. The tale tell signs that your heater core has sprung a leak, it is unlikely that you will see any coolant as due to the design of the heater plenum several pints will have to leak before it can spill from the plenum.

Parts you will need

  • 1 New heater core
  • 2 New worm drive hose clips
Tools for the job
  • ¼ drive socket set
  • Assorted screwdrivers
  • ½ inch wrench to disconnect the battery side cutters (you may need to cut the old worm drive clips off)
Safety first

Park on firm level ground. Apply the parking brake and place the gearshift into park. I would advise only working on a cold engine.

Lets get started

Working under the hood

Disconnect the battery ground wire. Unbolt the MAP sensor from the firewall, it is located just above the heater pipes and put to one side. Remove the two heater hoses from the heater core and plug the heater core with silly putty, blu-tack, a potato anything to stop the coolant spilling into the car later when removing the plenum (plastic case that houses the core). Just to one side of the two heater core pipes is a 7/16 nut, undo this nut (its one of three that secures the heater plenum to the firewall). Unplug the vacuum pipes from the TBL (Thermal blower Lockout) switch (it is the thing in one of the heater hoses) follow these vacuum pipes back to the firewall and there is a grommet, push this grommet into the car, there is also one other vacuum line to disconnect, follow it from this grommet to the vacuum manifold on the firewall and disconnect it from the manifold. Sometimes Ford put another 7/16 nut just near the vacuum pipe grommet under the wiper motor, if there is undo it.

Now move to the inside the car

Remove the dash pad, there are two screws in each defrost vent (don't drop them), one screw on each end by the "A" pillar and a row of screws along the edge above the speedometer. Undo all these screws and it should lift out. Remove the two insulator panels under the dash just above the drivers and the passenger's feet, they are held in place by some plastic poppers. Remove the left and right kick panels next to your feet on the "A" pillars, just a couple of screws securing then, you will need to loosen the sill trim to remove the kick panels. Remove the panel in the dash under the steering column, two screws holding this one. Remove the trim cowl from around the steering column a couple more screws for this one. Remove the glove box, three screws along the lower edge. Remove the floor duct from the plenum; there are two screws under the two vacuum servos and one plastic popper on the driver's side holding the floor duct to the plenum. On the passenger's side at the bottom of the plenum are two 7/16 nuts, undo these nuts they secure the plenum to the firewall. Pull off the vacuum line to the recirc door servomotor, that is above and to the right of the two nuts you just removed. Pull off the aspirator hose, this is the big white crinkly hose you see through the glove box opening. Looking up behind the radio you should see a vacuum pipe block connector, unplug this connector. On the right hand side, on the top of the plenum there is the ATC (Air Temperature Control) servo with a wire coming out of it, unplug this wire. Along the top of the instrument panel by the windshield there are a number of screws (six I think) these secure the instrument panel to the firewall, remove these screws. Remove the two bolts (one each side) revealed earlier by removing the kick panels, support the dash when doing this as it will now be fully unbolted.

This next bit is a lot easier if you can get a buddy to help support the dash panel for you but you can do it on your own, I have.

Working on the passenger's side you should be able to pull the instrument panel back about 4 to 7 inches, the dash will also slide up the steering column slightly, only an inch or two. Be a little careful with the instrument panel while it is unbolted, do not drop it but lower it gently, it is a little weighty, you will also hear a few creaking noises from the dash panel, do not worry about it. You will now need to pull the heater plenum off the firewall and pull the vacuum lines (remember the grommet earlier) through the firewall, and into the passenger compartment. These vacuum lines are behind the plenum on the driver's side. Now once again working on the passengers side you are going to have to go under the dash panel and lift it with your shoulder or back (or get a buddy to do it from the driver's side) and pull the plenum back until the heater core tubes are clear of the firewall, drag the plenum sideways towards the passengers side and rotate the top forward and down, you should be sort of screwing the plenum out from under the dash panel, lifting the dash panel so that the plenum can be dragged out from under it (you now know why you need to bung up the heater tubes if you didn't), the plenum comes out upside down. Removing the plenum can be a bit of a fiddle but it will come, just gently wobble it out while lifting the dash panel clear.

The heater core fits into the top of the plenum there are four screws that secure a cover that holds the core in the plenum. When refitting the new core always use the foam surround or a new one if it's a bit tatty.

In the tradition of all shop manuals simply refit in reverse order, don't forget to push the vacuum pipes through the firewall and refit the vacuum line grommet or reconnect the electrical connector on the ATC servo.

You might want to print this out and read it a couple of times but I think you should be able to do it in about 4 hours or so, it might look a bit of a task but it's really not that difficult, just take your time think a little about what you're trying to do, if you pull on the dash and it won't come try and see where it's stuck and look for another screw or clip.

If you have any questions just ask.

Happy (warm) motoring!


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