Draft on the feet while setting in the drivers seat.

Bob Dunahugh

New member
Sep 17, 2012
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We don't have our 78 GMC out much in the cold. Last week, when I was driving to Chicago for the show. The outside temp was 18 degrees out. It seems that there shouldn't be to many places as the soars. Or am I to much of a dreamer? Can someone clue me in on were to look? Bob Dunahugh Member GMCMI
 
Bob,

I THINK you're asking how to stop the cold drafts; if no, hit "Delete". :-)

I guess you know there is a "heater" vent right above your left foot, just
left of the brake pedal. By the time the "heater" air gets over there,
it's not very warm.

Probably the biggest drafts are coming from behind the cockpit side panels
-- once behind those, the cold air can easily get to you -- especially over
the tops of the panels beneath the dash. There are a couple of routes for
it take to get there:

At the sides of the firewall under the front hoods, there are gaps of 1" or
so between the vertical firewall and the coach sides. A big rope (wad) of
butyl gap filler there can take care of that for a long time.

The more difficult to fix gap is at the "chipmunk cheeks". If you're not
familiar with that term, it's what the bulge in the beltline just above the
front wheel wells is called. That bulging results from the coach skin
pulling away from the floor structure. Somewhere there's a good photo
article on how to fix it. Basically, one needs to remove the cockpit side
panels, the rubber in the beltline rub rail, and the wheel well liners.
Screws through the rail and the inside wall structure are used to pull the
skin back into place. Then, working inside the wheel well, fiberglass or
aluminum angles are epoxied to both the vertical and horizontal surfaces to
reinforce the screws and seal the joint.

With the side panels off, it's a good time to shoot "Great Stuff" foam
along all the seams, and install whatever else you want in that now
basically uninsulated area.
If you don't have chipmunk cheeks, just that may be all you need to do.

IIRC, Richard Sowers did the article mentioned, but I can't find it. But
I'm sure you'll devise your own specific ways to solve those problems.

Ken H.

> We don't have our 78 GMC out much in the cold. Last week, when I was
> driving to Chicago for the show. The outside temp was 18 degrees out. It
> seems that there shouldn't be to many places as the soars. Or am I to much
> of a dreamer? Can someone clue me in on were to look? Bob Dunahugh Member
> GMCMI
> _______________________________________________
>
 
> Bob,
>
> I THINK you're asking how to stop the cold drafts; if no, hit "Delete".
> :-)
>
> I guess you know there is a "heater" vent right above your left foot, just
> left of the brake pedal. By the time the "heater" air gets over there,
> it's not very warm.
>
> Probably the biggest drafts are coming from behind the cockpit side panels
> -- once behind those, the cold air can easily get to you -- especially over
> the tops of the panels beneath the dash. There are a couple of routes for
> it take to get there:
>
> At the sides of the firewall under the front hoods, there are gaps of 1" or
> so between the vertical firewall and the coach sides. A big rope (wad) of
> butyl gap filler there can take care of that for a long time.
>
> There is this
http://bdub.net/gmcmotorhome.info/skin.html

ERF

The more difficult to fix gap is at the "chipmunk cheeks". If you're not
> familiar with that term, it's what the bulge in the beltline just above the
> front wheel wells is called. That bulging results from the coach skin
> pulling away from the floor structure. Somewhere there's a good photo
> article on how to fix it. Basically, one needs to remove the cockpit side
> panels, the rubber in the beltline rub rail, and the wheel well liners.
> Screws through the rail and the inside wall structure are used to pull the
> skin back into place. Then, working inside the wheel well, fiberglass or
> aluminum angles are epoxied to both the vertical and horizontal surfaces to
> reinforce the screws and seal the joint.
>
> With the side panels off, it's a good time to shoot "Great Stuff" foam
> along all the seams, and install whatever else you want in that now
> basically uninsulated area.
> If you don't have chipmunk cheeks, just that may be all you need to do.
>
> IIRC, Richard Sowers did the article mentioned, but I can't find it. But
> I'm sure you'll devise your own specific ways to solve those problems.
>
>
> Ken H.
>
> On Mon, Dec 1, 2014 at 7:04 AM, Bob Dunahugh
> > We don't have our 78 GMC out much in the cold. Last week, when I was
> > driving to Chicago for the show. The outside temp was 18 degrees out. It
> > seems that there shouldn't be to many places as the soars. Or am I to
> much
> > of a dreamer? Can someone clue me in on were to look? Bob Dunahugh
> Member
> > GMCMI
> > _______________________________________________
> >
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>


--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://bdub.net/gmcmotorhome.info/
Alternator Protection Cable
http://bdub.net/gmcmotorhome.info/APC.html
 
> "Draft on the feet while setting in the drivers seat. [message #266958]"
>
> We don't have our 78 GMC out much in the cold. Last week, ...

Several years ago, back in the days when I only had one GMC, we had to make a trip during the winter to attend a funeral. I had previously noticed a
lot of drafts from the ends of the firewall on my 1973 coach and knew we'd freeze during the trip if something wasn't done.

Not having the time to do the work "correctly" I filled the gaps at the ends of the firewall with "Great Stuff" spray foam. I also used the same can
to fill the gaps around the rear wheel-wells. (Once used the can needs to be used up of it will go bad.) I painted over the exposed foam in the
wheel wells to help it last.

For two seasons the coach was used, with no issues with drafts in the cockpit or water seepage around the wheelwells. Then the coach was parked. The
foam still looks the same several years later.

The PO of my '78 had already sprayed foam in many areas including the ends of the firewall. The first layer of foam looks to be a different foam that
isn't holding up as well. I suspect it was a "latex type" of spray foam.

--
Mike Miller -- Hillsboro, OR -- on the Black list
(#1)'73 26' exPainted D. -- (#2)`78 23' Birchaven Rear Bath -- (#3)`77 23' Birchaven Side Bath
More Sidekicks than GMC's and a late model Malibu called 'Bo'
http://m000035.blogspot.com
 
Bob,
All of the above are good issues to check and fix. A smaller one you might look at is the seal where the speedo cable goes through the front of dash.
I intentionally left mine loose when running some cruise control wiring, and not driving my coach much in the cold either, was shocked at how much
cold air can come through such a little hole. I just butyl taped over it for a quick fix, and it was a noticeable improvement. I still need to go
after all those other gaps.
--
Craig Lechowicz
'77 Kingsley, Waterford, MI
 
Like Craig said, all of the above but I would like to add I have found over
the years all that because the body nose looses adhesion of the body to the
inner support structure. Screws through the beltline yes, also an
adjustable cross cable between the headlight baskets will help bring and
hold the front together. Any small penetration in the front will let air
in with the compression of air that's in the front underway. A #8 screw
hole will do the trick. Fore sure openings where cables and wires pass
through. Heck, seal anything you see but bringing the body back together
and resealing that inner to outer body seam that's wide open will be where
to start

On Mon, Dec 1, 2014 at 6:17 PM, Craig Lechowicz
wrote:

> Bob,
> All of the above are good issues to check and fix. A smaller one you
> might look at is the seal where the speedo cable goes through the front of
> dash.
> I intentionally left mine loose when running some cruise control wiring,
> and not driving my coach much in the cold either, was shocked at how much
> cold air can come through such a little hole. I just butyl taped over it
> for a quick fix, and it was a noticeable improvement. I still need to go
> after all those other gaps.
> --
> Craig Lechowicz
> '77 Kingsley, Waterford, MI
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
 
What Ken and others stated. I used clear "Through the Roof" flashing sealant in a quart can. It is similar to Goop in the tube but flows a little
better. Drys very clear , strong but flexible. Paint on with a 2" brush following the remnants of the factory tar they hoped would seal and last. Sort
of rebonds the panels whereas Great Stuff won't add much from a structural standpoint.
--
John Lebetski
Woodstock, IL
77 Eleganza II
Source America First