How do you change a heater core on an '88 GMC pickup?

Answer 1

This is very difficult, it is under/behind the dash on the passenger side. You will need to remove the entire dash and still you will be swearing in sentences, I strongly suggest you let a shop do this, it will be worth it.

If you can afford to take it to a shop , then go for it . The labour cost will be brutal .If you can't afford it and you are mechanicly inclined and have the time , give it a go .I just changed the heater core on my 1993 GMC Suburban in my driveway .It took me 3 hrs and a little swearing and I did not remove the dash . You pull out the glove box completely and remove the bolt that holds the dash to right side of the cab .This will allow you to raise the dash up a few inches . Remove the screws that hold the cover in place to get at the core . The screws that are at the back against the firewall are a pain to get at . A screw holds a clip that fastens the core in place . Under the hood you will have to take the remove the two hoses from the core tubes and then gently remove the core from under the dash .Do everything in reverse to reinstall the new core .