67 gs340 factory air heater core replacement

Discussion in 'The Big Chill' started by buickbill, Aug 18, 2018.

  1. buickbill

    buickbill Well-Known Member

    my heater core has been fogging up the windshield for ever , but don't drive it much in the winter , so been putting it off ! now , just fired up the a/c and its leaking pretty good . should coolant even be in the core with a/c on ? I replaced the vacuum switch on the mtr. not long ago . does the vacuum open the valve ,or close it ? I put a core in my 64 special last year. is a a/c car much harder ? 64/67 are the same under the dash , right? who has the best deal on htr cores ? also does anyone have a diag. of the vacuum lines . I have 3 going in the firewall ,1 going to a diaphragm , which needs to be replaced . I think it should have 2 lines ,but one is broke off . and one to the engine block coolant switch . thnx for any help, or a good link ,bill
     
  2. buickbill

    buickbill Well-Known Member

    well , not a lot of feedback . guess its all been said . ive tried to go back and find the answers . but their buried deep . just a vacuum line diag. would get me on the right track . can I calibrate my poa myself ? must you change the condencer . cant remember for sure , but it seams like I just flushed the system and replaced the dryer ,sucked it out and put 134 in it . and it blows sorta cold . seams like with the poa calibration it might be suff..
     
  3. 12lives

    12lives Engage! - Jean-Luc Picard

    I'm getting ready to do a 67, but not yet - can't help, but maybe I can learn from you!
     
  4. Ziggy

    Ziggy Well-Known Member

    Vacuum opens the hot water valve. Heater core replacement is a big job, but not impossible. The air plenum has to removed from inside the car because it carries the heater core in it. Remove the A/C duct connector, glove box lid and liner, three mode control cables, large clamp/seal at the right cowl, and a number of nuts from the engine side, and two heater hoses and its loose. Get new a/c box seals, the originals will be toast.
     
  5. buickbill

    buickbill Well-Known Member

    thnx , that xlns the core leaking while I was trying to see if the air was putting out . so if I leave that of , might bee able to put of the swap to winter . so one line is vacuum in , one goes out to htr. valve , and the third to the air dverter , right? the def. must be manually switched , by cable ?
     
  6. 12lives

    12lives Engage! - Jean-Luc Picard

    Hows it going?
     
  7. buickbill

    buickbill Well-Known Member

    havnt touched it . got a 70 lark .ive been playing with . want to clone another gsx . got a 70 electra to donate mtr., but havnt did much on it .been to busy to do much . to little time . tooo many projects!!
     

Share This Page