85 Sub heater core

[rke1]

I'm replacing the heater core on my '85 Sub 6.2 w A/C. My service manual shows all fastners to the module under the dash. It sure looks to me that they go through the firewall and must be reached from under the hood. That will mean taking off much of the rubberized shielding behind the A/C drier and fuel filter.

Anyone that has done the job and could offer advise would be welcomed.

[catmandoo]

if i remember correctly there is 3 nuts from the front side 2 on the bottom and 1 to the right of the blower motor as you look at it from the front and you will have to take that insul; off.

[grape]

You'll miss one of the bolts if you don't go ahead and take the inner fender liner out.......done it twice now on the same truck.

[catmandoo]

aren't those hell i forgot about that one but if i remember you can get to it with a swivel on a socket and long extension.

[cschneider]

There is actually one bolt and three nuts. There is the one bolt closest to the passenger door, inside the cab and two nuts underneath the housing on the firewall and one that is right underneath and to the left of the fuel filter. I have done this about four times and agree that the easiest and fastest way is to take out the wheel well.

[john8662]

Definitly the wheel well, There are as stated the main bolts/nuts plus the small bolts that hold on the plastic noise material. I would totally put that back on.

[rke1]

I finally did the replacement. The previous posts were VERY helpful. I did remove the inner fender panel -- I would think it would be almost impossible to do the job without removing it. I also had to remove the fuel filter housing and the A/C drier. It might be possible to leave the drier in place but I am also replacing and recharging all the A/C components so it was no big deal. I had previously cut and RTV'd back together the rubberized insulator to access the heater blower so that made the job a bit easier.

When the heater module is removed from under the dash there is a knockout plug to access a bolt that holds linkage and you do have to drive out (lightly) a rod that allows a flapper to rotate.

All in all its not a pleasant job but would be a lot easier the second time around.

Thanks again for the help........