Heater core

[blank]

Chuck,

I opened my heater box up last year to replace the weatherstripping inside.
It's fairly easy to open up the front of the box by removing the sheet metal
screws holding it on. You'll also need to peel off the foam seal where the
tubing enters the box(put it back on with 3M weatherstrip adhesive - don't
even think about using any other brands). Once you're inside, you can
determine if the core is leaking(it's right up front). I think you can
remove it if necessary with just the front off the box. If not, it'll be a
bear to get the box out as that was my original plan until I got a good look
at it.

HTH,
Patrick

>
> On my way home from Florida developed a leak in my heater
> core (I think) looked at the manuals, then at my GMC, and
> wondered how do I get to that core, anyone tried to take
> one out recently, how difficult is it, do I try or take
> it to my friendly GMC repair person with Greenbergs card.

 

[al chernoff]

I plan on doing my heater/ac box. Any special 3m weatherstripping needed.
what size, width etc. tia
al

> Chuck,
>
> I opened my heater box up last year to replace the weatherstripping inside.
> It's fairly easy to open up the front of the box by removing the sheet metal
> screws holding it on. You'll also need to peel off the foam seal where the
> tubing enters the box(put it back on with 3M weatherstrip adhesive - don't
> even think about using any other brands). Once you're inside, you can
> determine if the core is leaking(it's right up front). I think you can
> remove it if necessary with just the front off the box. If not, it'll be a
> bear to get the box out as that was my original plan until I got a good look
> at it.
>
> HTH,
> Patrick
>

> >
> > On my way home from Florida developed a leak in my heater
> > core (I think) looked at the manuals, then at my GMC, and
> > wondered how do I get to that core, anyone tried to take
> > one out recently, how difficult is it, do I try or take
> > it to my friendly GMC repair person with Greenbergs card.

 

[blank]

Al,

I used weatherstripping from Home Depot. IIRC, it was 3/8" wide by 1/8"
thick. I only used the 3M weatherstrip adhesive(NAPA) to reattach the
original foam seal where the heater core tubing sticks out of the heater
box.

Patrick

>
> I plan on doing my heater/ac box. Any special 3m
> weatherstripping needed. what size, width etc. tia
> al

 

[al chernoff]

Thanks patrick... just another question: unserstand all the openings are
pretty well shot, so what do we use to fix the various flaps. tia.
al

> Al,
>
> I used weatherstripping from Home Depot. IIRC, it was 3/8" wide by 1/8"
> thick. I only used the 3M weatherstrip adhesive(NAPA) to reattach the
> original foam seal where the heater core tubing sticks out of the heater
> box.
>
> Patrick
>

> >
> > I plan on doing my heater/ac box. Any special 3m
> > weatherstripping needed. what size, width etc. tia
> > al

 

[blank]

Al,

I didn't have any problems with openings or flaps - just the old foam was
falling apart. I scraped it off with a putty knife as best I could, sanded
the surface and spray painted it to give the new weather strip a clean
surface to bond to. The worst one was the recirc damper as it's at the back
of the left side of the box - it's tough to get two hands in there to do the
work. I put a mityvac pump on the damper vacuum pot to hold the flap open
and just did the best I could.

If you must repair or replace a damper, then I'm pretty sure that the box
must come out.

The foam works not only as a seal, but also as insulation, so you must cover
the entire surface of one side of the flap. If you could find some
self-adhesive foam about 4 inches wide and 1/8 inch thick, that would
probably work best as you could cut it to fit the entire surface. I just
used the 3/8 inch(might have been 1/2 inch - CRS strikes again) wide in
strips to cover the surface.

hth,
Patrick

>
> Thanks patrick... just another question: unserstand all the
> openings are pretty well shot, so what do we use to fix the
> various flaps. tia.
> al