anyone replace a heater core in a 69-72?

[70jimmy#2]

Tried to replace the heater core yesterday. Nightmare. To access the heater core you have to remove the heater box on the fire wall, which sounds simple but one of the bolts you can't access because of the fender skirt. The Haynes manual calls for loosing the fender skirt to access this bolt. The problem is that the bolts connecting the fender skirt to the fender bolt into nuts that are spot welded, well half of the welds broke leaving the bolts spinning in place and you can't reach the other side to secure the spinning nuts. I know I could hack the bolts off but I would have to have new welds made on the fender. I'm pretty sure you can't remove the core from under the dash. Anyone successfully replace their core in a 69-72? I attached a photo of the heater box and one of the truck since I've never put any photos up before.

 

[BUDDY]

Well, what I did on mine was just cut out a piece so I could pull the core out of the box from the front. Then I just siliconed the hole back up with the piece that I cut out with a cut-off wheel and it works like a charm. This way next time I do it I won't have to "loosen" the fender and possibly never get it back the way it was.

HTH and Good Luck,

Buddy

I've got my dream truck and it's a 72 K-5 that is getting there!!

 

[blazer72]

I pulled the innerfender off to replace mine! It was less work in the long run and real did not take long! Y can get to the backside of all the bolts to hold the wellnuts the snaped off and then replace them and the bolts or jusr drill out the bolt from the front side. The innerfender will drop out even the battery tray will stay put.

I understand the jeep thing I drive a BLAZER!!

Ken

 

[Blazer1970]

The nuts are not welded to the back side of the fender. There are clips that clip over the inside of the outer fender that have the nuts welded to them. Grind off the heads of the rusted bolts, remove the inner fender, fix your heater core, then buy new clips and factory style bolts from Chevy Duty or LMC and put it back together.

Tim

70 Blazer CST 4X4 350 SM465 NP205
87 Burb 4X4 350
01 GMC 2500HD 4X4 Duramax/Allison

 

[70jimmy]

I did it. Dropped the inner fender well, But didnt have aproblem iwth rust. Looked like someone did it before me and either didnt bother putting all the bolts back or busted them. Now I know how to get my fender back where it belongs. Also clean out you cowl and you might check into a screen to stop debris from getting in there. My heater core area was full of dead leaves. Darn now I have another project.