Heater Core Removal & Installation - non-A/C '70 A-Body

Discussion in 'The Big Chill' started by john.schaefer77, Jan 22, 2018.

  1. Brett Slater

    Brett Slater Super Moderator Staff Member

    I should be so lucky. Haha

    I'm literally in the middle of the whole process right now. 4 of the 5 bolts are off and the glove box is out.

    Getting the heater cables separated from the box (which looks to be a real pain) is on the check list that also includes the elusive nut.

    How did those tubes fit through the firewall on Goeff's car?
  2. TORQUED455

    TORQUED455 Well-Known Member

    The tubes fit through the firewall just fine, but you really need 2 people or risk doing damage. The blue cable is the one you have to worry about. Very easy to break the mounting tabs. Geoff’s had a different brand (incorrect length, ends and a plastic-type core) already broken too. Take your time! These old things are really getting difficult to work on.
    Brett Slater likes this.
  3. Brett Slater

    Brett Slater Super Moderator Staff Member

    It was a miracle but I managed to get that nut off.

    I borrowed a very thin (and long) flat 1/4 inch ratchet from my mechanic friend and was able to strategically slip the socket over the stud, getting a few turns on it. Then, I did the rest with my fingers and kept a magnet close by in an effort to keep the nut from dropping.

    It was a small victory but I'll take it at this point.

    The box is home and will get cleaned up, new padding and some 3M caulk strip where the core sits. The plan is to reinstall later this week.

    20190805_173209.jpg 20190805_165925.jpg 20190805_181521.jpg 20190805_180936.jpg
    john.schaefer77 and Utah455 like this.
  4. Utah455

    Utah455 Well-Known Member

    Take some good pics of sealing it back up. I need to do mine.
    Brett Slater likes this.
  5. copperheadgs1

    copperheadgs1 copperheadgs1

    Just use 3m strip caulks. Look at the way the factory did it. They didn’t use any goofy gaskets.

    Look at the vent doors in the inside box. The rubber padding on those vent doors is always disintegrated. Right Brett?

    Get new rubber and glue it to the doors. If you don’t they clank when you move the vent levers. Also the box will leak heat all the time. Ever wonder why your legs are hot? The front part of door is easy. The back is not. You need to reach in from behind and your hand can get stuck. Find a sharp kid or maybe your wife that has skinny arms to do it if you can’t. Paint contact cement on the rubber and work fast or that glue will stick to something you don’t want it to. I have done a few.

    Don’t neglect this. It’s out and you want to take care of everything. The defrost duct seal is usually in good shape. That is good as I think you would have to break the box apart to get at that.
    Last edited: Aug 6, 2019
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  6. Brett Slater

    Brett Slater Super Moderator Staff Member

    The padding on the doors was all but gone.

    New stuff will be here today, via Amazon. 1/8" thick, non-adhesive. I bought a substantial amount, so when I screw up the back of the door, I'll have enough to compensate.

    I have the 3M caulk strips and plan in using this glue for the padding.

  7. Brett Slater

    Brett Slater Super Moderator Staff Member

    Another thing I noticed that should make installing easier is: removing the screws from each cable. That releases tension when trying to get those pesky retainers off.

    Speaking of which - the one closest to the driver's side didn't have a retainer but I have extras on hand. Also, when putting the box back in, I think it's going to behoove me to keep it tilted (toward the back of the car) when putting the cables back on the box.

    With all three screws removed from the brackets and the box titled back, popping the cables/retainers back on looks to be much easier.
  8. copperheadgs1

    copperheadgs1 copperheadgs1

    Will also keep you from getting concussed from smacking your head on the metal dash.
    Brett Slater likes this.
  9. StfSocal

    StfSocal Well-Known Member

    This seems to be a project that everyone is doing right now! Makes sense to do before the cold weather gets here.

    My heater core is at the radiator shop now getting re-cored. In the interim I am in the process of cleaning the box and laying new sealant. I got a seal kit for the AC & Heater boxes, its pretty much useless but there are some that I can use. I will be taking pics of the re-assembly and posting them on my thread in the "Big Chill" section. Hopefully this will help anyone else doing this project.

    I completely disassembled my heater box to clean it.

    Good luck on your project Brett!
    Brett Slater likes this.
  10. Brett Slater

    Brett Slater Super Moderator Staff Member

    Yes - seems like this is the trendy project.

    How laborious was disassembling the box? That could make some things a lot easier for me.
  11. StfSocal

    StfSocal Well-Known Member

    Very simple. My car has AC so not sure if its apples to apples here, but i assume its close. There were three small pop rivets that i had to drill out, but other than that its just a bunch of screws to remove.
  12. Brett Slater

    Brett Slater Super Moderator Staff Member


    I'll move this to the "Big Chill" forum as well.
  13. buick64203

    buick64203 Just plum crazy Staff Member

    Ben there, done that ion the Aquamist car. I also tackled a list of "while Im there" projects at the time that included replacing the plastic V shaped defroster ducting and refurbishing the instrument cluster. I look back at some of these major projects Ive done and wonder how I got the motivation to do them.
    Brett Slater likes this.
  14. Brett Slater

    Brett Slater Super Moderator Staff Member

  15. buick64203

    buick64203 Just plum crazy Staff Member

    I upgraded all my Snap on ratchets years ago to the fine tooth style. They're 80 tooth. The 1/4" ratchets are 72 tooth. Really makes a difference when its super tight and there is no clearance for the swing of the ratchet. And having some that are flex head really helps too
    Brett Slater likes this.
  16. Brett Slater

    Brett Slater Super Moderator Staff Member

    This thing worked like a charm! A few turns to loosen it and the rest by hand.
  17. buick64203

    buick64203 Just plum crazy Staff Member

    And people ask me why I have so many tools. That's why!
  18. Brett Slater

    Brett Slater Super Moderator Staff Member

    The family friend and former Buick mechanic (and original '70 Stage 1 owner) who helped me the other night said it best: "you can never have enough tools."
  19. StfSocal

    StfSocal Well-Known Member

    It's no problem with the engine out and front clip off :p;):D:D
    Brett Slater likes this.
  20. copperheadgs1

    copperheadgs1 copperheadgs1

    That’s how I do them!
    Brett Slater likes this.

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