Tips on Heater Core

Discussion in 'The Big Chill' started by 68Rivi_In_Cali, Nov 10, 2017.

  1. 68Rivi_In_Cali

    68Rivi_In_Cali Well-Known Member

    Wellll I thought and hoped I would never see the day but since I have my dash and interior gutted, I might as well replace the heater core. I have read up on the guide on the buick performance website but one step they make sound easy is getting the bolt thought the front right fender well. I don't want to cut an access home and I really do not want to remove the fender since I removed the driver side and it threw off the alignment already.

    I've been reading up on past threads and some mention being able access it without taking the fender off but there are no real detailed descriptions.

    Any tips on removing the inner fender well? The car is a 70 Skylark with AC, so the box is in the way as well.

    I jacked up the car, removed the wheel and unbolted the inner fender but I don't see a way for it tonslide out. maybe shifting it forward enough to reach my hand in? Even then it's tough -_- .

    Anyone in San Jose CA that would want to get paid in beer and food to help? Haha one way or another I'm getting this done

    Thanks in advance guys
  2. Brad W

    Brad W Miles from nowhere...

    I'm in the same boat you're in. I'm installing a A/C delete cover and I've gotten a lot of good advice from this forum. So far I've removed all the bolts holding the inner fender to the point where I can move it with my hands, my next step that was suggested was to jack the car up and remove the front wheel and to re-leave tension that maybe on the inner fender and to have better access. I'll be doing that tomorrow, hopefully I'll have some luck.

    I'll let you know how it goes.
  3. TrunkMonkey

    TrunkMonkey Well-Known Member

    Tie a piece of webbing like you find on the smaller cargo straps between the lowest bolt hole on the bottom outboard side of the fender well, and then upper inboard side hole making a loop and then use a stick to "wind up" the slack in the strap.

    This will draw the fender well up enough that it will "drop" out the back.

    Most of the time, the hang up is the lower outboard part of the fender well where it slips past the inner lip of the fender (along the bolt line). I have done this on several heater core replacements.

    I have also managed to use a block of 2x4 back behind the wheel well and just under the heater blower case half and been able to get a ratchet wrench on the nut or bolt after removing all the fender well bolts. It's very tight, but can be dome.

    And leaving the nut or bolt out/off (just in case) when I put things back together.
  4. 68Rivi_In_Cali

    68Rivi_In_Cali Well-Known Member

    Thanks for the tips guys. Here's what I ended up doing. After evaluating the condition of my inner wheel well, I decided to cut an access hole. I am going to buy a plug for it but it made it way easier. I now am moving to the inside.

    Looks like someone had previously removed the bit behind the engine/ firewall so I had a nice head start.
  5. 68Rivi_In_Cali

    68Rivi_In_Cali Well-Known Member

  6. TorqueMonster1

    TorqueMonster1 Making My GS Great Again!

    I’ll add my 2 cents worth to this post. My comments are about the heater core itself. Mine has no issues as of now. However, since I’m doing a complete restoration on my GS I will be doing “something” with mine. I had originally thought I’d just replace it with a new one. I got a new “repo” from CARS INC, There is nothing wrong with it Except that’s its aluminum. I don’t think that I’ll go that route. All I’ve come across from any sources are aluminum. So, I’m leaning towards having my existing/original one checked out my a professional and putting it back in. Someone may have a NOS which I’d consider but I just don’t think I want an aluminum repo. My comments my be a little off topic but replacing a heat core is no small task so I wanted everyone thinking about it to have as much info as possible. Thanks, Mark
    Last edited: Nov 13, 2017
    1973gs and 68Rivi_In_Cali like this.
  7. 68Rivi_In_Cali

    68Rivi_In_Cali Well-Known Member

    Thanks for the input Mark.

    I noticed that all the part stores near me only carry the aluminum ones as well. I will also save the original one as well and get it repaired for future use .
    TorqueMonster1 likes this.
  8. 68Rivi_In_Cali

    68Rivi_In_Cali Well-Known Member

    Hey guys I'm going to just keep updating the thread in case someone else is on the same boat.

    I was having a hard time removing the box from under the dash.Turns out I was missing a bolt on the top part of the box holding to to the firewall. The underdash insulation was hanging down and covering it.

    It was located near the selector cable that needs to be removed.

    Once it was removed, the box slipped out fairly easy. Just make sure you note where the vac hoses go and or route them away from the box so they don't get caught.
  9. 68Rivi_In_Cali

    68Rivi_In_Cali Well-Known Member


    This is where there last bolt I didn't see was.
  10. 68Rivi_In_Cali

    68Rivi_In_Cali Well-Known Member

  11. 68Rivi_In_Cali

    68Rivi_In_Cali Well-Known Member

  12. 68Rivi_In_Cali

    68Rivi_In_Cali Well-Known Member

    Ohhh I like this idea, I will try for sure.
  13. TrunkMonkey

    TrunkMonkey Well-Known Member

    I forgot to mention to "secure" the stick once you have it wound up, so it is the same when you put the wheel well back in.
    And not too tight. You don't want to bend it, only "bow it". :)
    68Rivi_In_Cali likes this.
  14. mikethegoon

    mikethegoon Well-Known Member

    Ill have to do something better for my 68 this winter. Picked up a heater core off bay and gonna take it and car to local shop for R R. Manual says to drill out the studs that are hard to get to. Anybody try this?
  15. 68Rivi_In_Cali

    68Rivi_In_Cali Well-Known Member

    I have heard of this trick as well. I was more worried about cracking the box by drilling. The fender hole didn't need to be as big and I can always buy a plastic plug to cover it. I resorted to this due to the Wheel well having rust issues under the battery tray. I will be removing it in the future. So far as long as its a daily driver/ not a GS and don't mind an access hole in the inner fender, then the hole method seems easy and quick to do.

    I want to do one of those Vintage air units in the future.
  16. gstewart

    gstewart Well-Known Member

    When I had the engine out of my car in April/May, I decided to replace the heater core. I had already removed the fender liners for repainting.
    The heater box was relatively easy to remove & made it so because I had removed the buckets & console. With the heater core mounted to the heater box, I discovered that one of the core's pipes had to be bent slightly. But it was a bi?ch reinstalling the whole mechanism.
    The old heater core, I believe, was the original and with no leaks and still function.
  17. mikethegoon

    mikethegoon Well-Known Member

    I am soaking bolt with kroil - hope I don't break seat bolts off. I figured to remove console too. That access hole thru fender well looks good in the right spot. Ill have to start looking fore hole saw and plug. I dot remember heater box being that big. But I remember pain in the.....
  18. BadBrad

    BadBrad Got 4-speed?

    Just FYI for the next guy - don't cut that little hole all the way around. Just go about 345 degrees. Then you can just bend down the flap, access the bolt, push the flap back up, seal the gap with goo, or even tack-weld it.
    Harlockssx likes this.
  19. 67340

    67340 Member

  20. Doo Wop

    Doo Wop Where were you in '62?

    Rather than a dead link, here you go.

    The Old Guy said:Here we go again!! The manual says to remove the fender, but if you look at the plastic cover over the assembly on the inside of the car, you will see in the bottom right hand corner, a round emboss. If you drill a 5/16 hole through the middle of the emboss, you will take out the stud that requires the fender removal. Then follow the directions in the manual and you can pull the core. When reassembling the unit, a little dum-dum in the hole will disguise what you did, and the three remaining bolts hold the assembly just fine.
    :beer :beer :beer :beer :beer :beer :beer :beer :beer
    :Dou: :Dou: :Dou:

    Used your tip on drilling out the bottom right corner stud. Worked great. Only a couple of hours to do the re & re on my heater core today. That was on a 70 with a 350 and air.

    Took out the passenger bucket seat and passenger kick panel as well. Made it a bit more "roomier".

    Thanks again...great tip!


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