[Nickv]

Hi,

Seems my heater core in my 67 Grand Prix is leaking coolant inside on the pass. floor. How easy is it to replace the core? My GP has ATC A/C equipment. It looks like alot of work. Any tips or ideas?

Thanks

[one70gt37]

You're going to have to pull the pass. side inner fender well & remove what we call the outer suit case, then on the inside remove the heater box assy. & control cables & maybe the glove box, not a bad job but can be time consuming, you might want to replace while you're in there the motor blower too.

[Nickv]

That seems like it's overly complicated just to remove a heater core?? I got ahold of the service manual yesterday and it didn't seem to indicate any removal of fender wells or outside A/C box.

I'll take a look at it tonight.

thanks!

[perryka]

Nickv,

Not sure how ATC will impact the job, but for a standard A/C car:

You'll want to remove the underdash A/C vent/duct assembly, to get access and provide room to get the heater box out later. You need to remove the glove box liner to get access to the top of the heater box. On the heater box unit under the dash, there will be 4 main bolts you'll have to remove, 2 at the top and 2 at the bottom. They'll be over toward the right (passenger) side of the unit, as you lay there twisted on the floor looking at it. They surround the large part of the box that houses the core. You may have to peel back the carpet a little bit to find the lower 2, and move some insulation to get to the top 2. Over on the left side of the heater box, you'll need to remove the vacuum line, and there's another screw over there that'll need to be taken out. Once you get all that loose/removed, start to work the unit back away from the firewall carefully. Before you try to pull it all the way out, go back up and reach in through the glove box opening and remove the screw and clip that holds the temp cable to the cam assembly on top of the heater box. Here's where I'm not sure how the ATC system is different. On the standard A/C system, that cable has to be removed before you can pull the whole unit out from under the dash. Whatever connection there is for the ATC system will have to be released. After that, you can take the heater box out. Once you work the whole assembly out, to get the core out of the box, you'll need to disassemble part of the cam/lever assembly on top in order to get access to get the core out of the box. I suggest you have the new core already there, ready to go in. At least for me, it helped to be able to swap it out right there, because you have to reassemble that cam/lever assembly and it's a lot easier to put it back together right there after you just took it apart. It's easy to lose track of how it all fits together. The manual pictures help, but it still can be tricky. Once you get the new core in and the cam/lever assembly back together, just put it all back the way you took it out. Takes a little time, and you have to be somewhat of a contortionist to get to it all, but it's not that bad if you're careful as you go, and keep track of everything. Hopefully I remembered everything. Good luck.

Alan

[Nickv]

Thanks perryka!! That seems more like I suspected would be the procedure. Thanks for the information.