kansjfr

Ok, I just got my '68 442 convertible sort of roadworthy, found some gasoline leaks, fixed them, getting things sorted out, and no surprise, the heater core is leaking. Since the radiator was leaking, I figured the heater core was due to leak too. In searching this forum and the related links to the Chevelle forums, it looks like I have to take out the passenger side fender liner to get to the nuts on the firewall side holding the heater core to the firewall. Is there any way around this, since my car has been undercoated and it's really a mess trying to get to the fasteners under that goop? If not, I'll deal with it. Is the next step then to go under the dash and remove the heater box, and then take it apart to get to the heater core? Does it make it alot easier to remove the passenger seat? Also, my car does not have A/C, since it's a 4-speed convertible. The dealer who sold my best friend the car when he ordered it told him A/C was not available on a 4-speed convert. Any help/comments are appreciated.

oldcutlass

You can get to the one mount without taking the liner out, but will be almost impossible to put it back on. At least that's how my 67 was. Just because the radiator leaked does not mean the heater core will leak soon also. I'd leave it until it leaks.

hilbily

I would really like so see some opinions on this because I have a 68 coupe with air that needs a new heater core and I think I would rather have my *** kicked than replace a heater core, any advice?

droldsmorland

Remove the passenger seat, optional but much easier on your back-n-neck. Remove the passenger inner well. Its somewhat easier w/o A/C. Take your time mark things and take pictures if needed. Its really not that big of a job.
Do yourself a favor and completely flush the system, block rad, etc...Refill with pre-mix 50/50. Do not use tap water. Repplace the TStat with a high quality HD Stant. This system should be flushed and changed every few years regardless of mileage. PH test the system annually with test strips. H2O pump lube additive corrosion inhibitor optional.

442Harv

With no AC, it is not a bad job. If you don't want to take the inner fender off, you can drill that bottom fastner out. I would take the inner fender out. I also think you can loosen the bolts, and get access to the bottom one without removing, on non AC car.

kansjfr

Thanks for the replies. Sigh...I guess I'll go ahead and take the fender liner out and the passenger seat also. Do i have to take the chrome trim on the fender wheel opening off, too? By the way, my heater core IS leaking, alot. As an aside, I'm tickled to death that I got the old girl running and roadworthy (although no trips longer than a couple of miles for now) after not being tagged since 1983. Alot of good advice on this forum, thanks for all the help.

droldsmorland

If its been moth balled that long consider changing ALL fluids....p/s, brake, rear dif, trans, repack front bearings, bleed the brake system after replacing the 3 soft lines...etc...

kansjfr

Yeah, that's all been done, including new gas tank, radiator, wheel cylinders, brake lines, gas lines, belts, hoses, thermostat, etc. Everything is pretty good to go except the heater core.

kansjfr

Question and update: How many nuts/bolts need to be taken off on the firewall side of the heater core to get it to where it will come out? In preparing to take out my fender liner so I could get to the corner heater core nut on the firewall, I noticed a U-shaped cut in the fender liner, and sure enough, some lazy mechanic cut the liner instead of removing it to get to that heater core nut, and I found that the nut was removed, but never replaced. So, I guess I won't be removing the fender liner to get the heater core out, but how many nuts are there; in other words except for the one in the lower corner, are there any hidden nuts to remove? Thanks.

JohnnyBs68S

Its been too long since I did mine to remember the number of bolts / locations / etc. But I removed my hood & passenger side fender to replace mine, which made it easy to also replace the blower motor (the bearings were getting noisy) while I was at it. You'll want to get the main plenum off from under the dash (that has the air door) so that you can clean out all the dried gook that has probably been accumulated due to the leak. Lube up the control cables and levers while you're at it too.

RandyS

There are 7 fasteners. 5 are quite visible, 2 are hidden by the inner fender. Here is a pic of what to look for.

kansjfr

Thanks for the reply. I'm not removing the blower motor; does that mean I only have to remove the nuts that aren't holding the blower motor in, or do they (bolts/nuts holding the blower motor in) have to be removed, too. I can see 4 bolts/nuts now on that housing, and the one nut down in the very corner of that housing, under the blower motor, has been removed and not replaced. So considering that, is it now 4 or 6 nuts to remove to get only the heater core out, leaving the blower motor in place. Sorry for the confusion, and thanks for the reply, it's helpful.

z11375ss

Shoot. I removed my fender to do my last one and thanks to a chinaman the new one lasted all of about 300 miles before it gave way as well. Another winter project. Sheesh. Make sure you get a quality replacement is what I'm saying.

kansjfr

I bought a Spectra brand, a little more $, but not much. Hope it's ok.

z11375ss

One can only hope. Good luck.

kansjfr

Ok, got the heater core replacement done, and it was quite a pia. Did have to take out the fender liner, which wasn't too bad after finding tips on this forum on how to get it broken loose. Had to take off the enclosure on the engine side of the firewall, which also held the blower motor. Had to take the heater box out under the dash, after taking the glove box out. Disconnected all 3 cables, breaking one of the plastic brackets molded into the cable housing, replaced it with a generic cable clamp. Then took the old heater core out of the heater box, cleaned it up, put new core in heater box. Had to have help getting the heater core nipples through the firewall, and had to bend the curved nipple to get it through the holes in the firewall. Replaced the blower motor while I had it all apart. Had a friend hold heater box in place in the interior while I put the cover on the studs coming through the firewall on the engine side of the firewall. Then replaced the fender liner and tire/wheel. No way in hell could I have done it without help getting the damn thing to line up with the holes in the firewall. Message me if anyone needs any more specific info. thanks for reading, Mike.