Hi all,

Attempting to have my heater core flushed at a radiator shop as the heat is lack luster in my '76 cutlass.

I removed all the bolts (I think), pulled the radio forward, removed glove box, etc. A mess. Heater core is loose but won't come free. Feels like its stuck in just about the center. Will pivot around all axis but won't come free. Tubes are out behind firewall (just barely). Can't figure out what is preventing it from coming free.

Any ideas? I thought maybe a air door was bound up or something but the door lever moves freely. Had to quit for the night before I broke something from getting impatient.

Thanks for any insights!

p.s. - I followed the instructions here:
1973-77 Cutlass heater core removal guide WITH AC - ClassicOldsmobile.com

 

I got it out. I think it was hooked on one of the pipes coming through the firewall. The firewall is actually quite thick right there, with maybe two layers? leaving enough material for the pipe to get wedged in there.

 

Flushing can be done with the core in place. After flushing be certain they pressure test it for leaks.

Have you considered new since it is out? It would probably cost less than the flushing.

 

Hey - thanks for your comment. I did consider new but thought the original would likely be higher quality - Rad shop told me $40 for flush so am going that route. I considered the flush might be able to be done without pulling but then the shop has to work on the car and I just don't really trust them for that stuff (and I don't feel like flushing it at home - would that really do a good job and what do I do with all the waste water.. etc. Also I assumed pulling it would be easier than it was. Ha Ha. But now I can debate how to repair the foam on the heater core that has fallen apart in the 50 years.

 

I dunno. When I replaced my heater core ages ago, I had similar problems with getting the pipes into / out of the firewall holes, actually trimmed one of the holes to make it easier next time. Ended up stressing one of the tubes in the replacement and caused a leak. Glad I checked before putting it all back together. So there's a chance of causing damage each time a core is installed and removed. I would've flushed it in place, save a lot of work too if it doesn't leak.

 

Yeah, hindsight is 20/20. Ready to go back in. Hopefully no damage done.

 

Similar problems getting heater box back in as I had getting it out. Can't get the stud near the pipes through the hole while also getting the pipes through. A total b**ch. Tried for hours. Getting frustrated. Need to take a break for a while. The engineers really didn't provide any margin to get this in. Part of my problem is I haven't been able to get the console out. That shifter has the lever you pull up on that prevents easy removal of the console. Slid console back but not out. Getting in the way still. Might need to unbolt shifter from the floor and disconnect cable, then remove console and shifter together. What a total PITA.

 

So I got it back in. After many choice words were uttered. Removing the console made quite a difference, but the real trick was weaving the core up around/to the correct position relative to the defrost duct. A portion of the box needs to go behind the duct, and this is challenging because the pipes prevent the core from moving toward the firewall until they are lined up with the holes, etc. Anyway, putting this here so maybe someone in the future finds this thread and it helps.

 

Glad you got it back together.

I had a heater core leak in my '99 Dakota. After reading the shop manual and seeing that the entire dash needed to be removed and the A/C sealed system had to be violated, I took it into a shop for that job. I know my limitations. Most folks don't expect old cars such as ours to be this difficult.