Who can tell me about replacing my heater core?

Discussion in 'Buick FAQ' started by RANDY TAUSCH, May 11, 2004.


    RANDY TAUSCH Well-Known Member

    I have found that my heater core has a tiny leak. How difficult is it to replace? Is it one of those long drawn out jobs or is it pretty straight forward?
    Thanks for the help,
  2. 71 custom lark

    71 custom lark Senior Board Member

    It's a pain in the rear end. Has to be pulled from the inside and ac box in the engine compartment has to come off.
    EdwardBryan likes this.
  3. BadBrad

    BadBrad Got 4-speed?

    I wrote a story on here somewhere about how to replace this without pulling the fender. Does require partially (300 degrees)hole-cutting the wheelhouse with 1.25 inch bi-metal holesaw.

    Search the forums for the story.
  4. Yardley

    Yardley Club Jackass

    Geez, again I'm still amazed that the engineers did this. I know the engineers hadn't planned on these cars outliving most of the parts, but my 69 Riv has a 2 piece box and the heater core takes all of an hour to swap. It was a last minute design change, so at least on my model that thought about it.
    Gary Anderson likes this.
  5. Doo Wop

    Doo Wop Where were you in '62?

    Do a search for "heater core removal".

    Good luck.
  6. John Eberly

    John Eberly Well-Known Member

    Ouch Baby, Very Ouch!

    The book tells you to start by removing the front outer fender.

    Then the inner fender.

    Then the heater/AC box. There is ONE bolt you can't get to without tearing the front end apart.

    Then you can go inside the car and get the heater box out.

    I just saw some advice from Joe Taubitz on how to avoid all of that. Do like Doo Wop said, search the forum for heater core removal.

    If you go the whole front removal, replace the heater fan motor while you're at it.
  7. The Old Guy

    The Old Guy Joe Taubitz

    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:
  8. BadBrad

    BadBrad Got 4-speed?


    That's even easier than the way I did it (I think?).
  9. Doo Wop

    Doo Wop Where were you in '62?

    Thx For The Tip

    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!
  10. Carl Rychlik

    Carl Rychlik Let Buick Light Your Fire

    You've got to admit,it was a stupid design. When I was restoring my car,I replaced the heater core before putting the fender on. Certainly much easier at that time. I couldn't imagine pulling that fender back off my car after putting it all together. :rant:
    TorqueMonster1 likes this.
  11. 70gsrick

    70gsrick 1 of 66

    Is the procedure the same on a non A/C car?
  12. Truzi

    Truzi Perpetual Student

    It was fairly easy for me. I didn't know about the bolt that you have to remove from the engine side, so we accidentally pulled the box off it (stripped). We did it all from the inside.

    It'll take a little time, but is'nt that hard.

    Wish we had this board back then, I'd have taken more car to drill the box at that one bolt.
  13. sbbuick

    sbbuick My driving scares people!

    Awesome - very helpful.

  14. landshark

    landshark gearhead, railfan, maniac

    Heater Core

    In my 1970 chevrolet chassis service manual, under 'air distributor duct and core replacement, it says, "all except corvette - from under dash, drill out lower right hand distributor stud with a 1/4" drill. Don't these engineers aver talk to each other?
  15. 462CID

    462CID Buick newbie since '89

    Obviously, no :laugh:
  16. henry white

    henry white Well-Known Member

    what about if you already have the whole front clip off the car? ( 70 GS 350 with A.T. & air conditioning. i take it i must remove the A/C box under the hood? must i also remove the dash pad ? or just heater related parts on the inside of the car?

  17. Truzi

    Truzi Perpetual Student

    On my 70 'Lark I basically just removed the box inside the car (pulling it off without knowing about that one stud - stripping it out of the box). I didn't have to remove the fender or the A/C box under the hood, or the dash.

    Under the hood I believe the only thing I had to do was remove the hoses connected to the core. Watch for dripping fluid, or you'll have a mess.
  18. 86regalwith455

    86regalwith455 Well-Known Member


    ehi faqU all

    it's the more incredible ****in'forum with talkin'idiots
  19. mechacode

    mechacode Well-Known Member

    :error: :puzzled:
  20. 86regalwith455

    86regalwith455 Well-Known Member

    that post was not by me, time for me to change password!


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