how hard to replace heater core?

Ozsum2 said:

I just replaced my heater hoses yesterday, and after the glove box was out, it looks like it would have been a peice of cake. On my 67, I'm not so sure that the whole box had to come out. Just undo the control cables, then pop the clips and your home.

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geegee said:

A couple of cautions:

a. Remove hoses from engine side first then drain before attempting to remove heater box.

b. When removing heater box, pull disconnected hoses through the firewall to get sufficient room to work before attempting to disconnect the hoses from the heater core. If you wish to save the hoses, either cut short or remove from core. Some coolant is going to come out of the hoses so be sure to have a drip pan underneath the lines. Use a old bath towel under the drip pan just in case. When lifting the box out of the car be sure to hold the heater box and cores with the heater box nipples facing up. If you don't, you'll get a lot of coolant where you don't want it (all over the interior).

c. When separating the heater box halves be sure to remove clips carefully. If you just pry them off, some or a lot of the fiberglas comes off with the clip and then the clip has nothing to hang onto when you go to reassemble. If you do this then its either ingenuity or time for a new heater box...so be careful! If the clips go on to hard when reassembling, then lay them flat on concrete and using a small hammer hit them lightly on the arch. This flattens the arch and widens the clip. It goes on easier then but does not hold as tightly. The right touch with the hammer gives the correct result. Don't use clips that are either sprung or too flattened. You can get replacements at the Mustang parts store cheap. Its the box that's expensive.

d. If you want the heater to work well, then be sure to put a new gasket kit in it. About $20 for the kit. Plus a couple dollars more for some aerosol spray glue (needed to attach the gaskets and foam insulation).

e. Check the fan motor while the box is out. No sense of doing all this work and then finding out you need to replace the fan motor. The fan motor can be checked by simply connecting it to a 12v battery. No, it won't hurt to hold it in your hands when testing it.

f. Use a flat black aerosol paint to lightly paint the box while its out. It looks a lot better when a light coat of flat black paint covers the worn gray look that the box gets with age.

Good luck!

Jeff

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