Water Leak - above steering wheel

[billvv]

We have a leak that drips from the front cap at the windshield down to the horn button on the steering wheel. This morning, after the first fall rain,
I went to move the coach and it wasn't until I went in reverse that the leak started; I assume there was water sitting nearby and the movement caused
it to migrate to the spot where it always leaks.

Looking for photos or description of that area above the front cap to try and get ideas why the leak would expose itself at that location and
therefore find the source. We have an outside visor above the windshield and the normal running lights on the roof. A PO had spread silicone sealant
along the top of the windshield rubber on the outside, and I dug it out and used some better stuff.
--
Bill Van Vlack
'76 Royale; Guemes Island, Washington; Twin bed, full (DS) side bath, Brazilian Redwood counter and settee tops,455, 6KW generator; new owner a/o mid
November 2015; Since arrival: New HVAC blower, heat flap cable, headlight switch.

 

[Jim Hupy]

Most of the time, the clearance lights are the guilty party. But, also look
at the T.V. batwing antenna. Don't know about the visor but, any roof
penetration should be suspected until proved innocent. Lastly, the roof
cap, where it joins the metal roof.
Jim Hupy
Salem, Or
78 GMC ROYALE 403

> We have a leak that drips from the front cap at the windshield down to the
> horn button on the steering wheel. This morning, after the first fall rain,
> I went to move the coach and it wasn't until I went in reverse that the
> leak started; I assume there was water sitting nearby and the movement
> caused
> it to migrate to the spot where it always leaks.
>
> Looking for photos or description of that area above the front cap to try
> and get ideas why the leak would expose itself at that location and
> therefore find the source. We have an outside visor above the windshield
> and the normal running lights on the roof. A PO had spread silicone sealant
> along the top of the windshield rubber on the outside, and I dug it out
> and used some better stuff.
> --
> Bill Van Vlack
> '76 Royale; Guemes Island, Washington; Twin bed, full (DS) side bath,
> Brazilian Redwood counter and settee tops,455, 6KW generator; new owner a/o
> mid
> November 2015; Since arrival: New HVAC blower, heat flap cable, headlight
> switch.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[jim kanomata1]

Check the seam that the front cap connects to the aluminum roof. Also all
marker lights ad lense.

On Sat, Sep 17, 2016 at 12:35 PM, Bill Van Vlack
wrote:

> We have a leak that drips from the front cap at the windshield down to the
> horn button on the steering wheel. This morning, after the first fall rain,
> I went to move the coach and it wasn't until I went in reverse that the
> leak started; I assume there was water sitting nearby and the movement
> caused
> it to migrate to the spot where it always leaks.
>
> Looking for photos or description of that area above the front cap to try
> and get ideas why the leak would expose itself at that location and
> therefore find the source. We have an outside visor above the windshield
> and the normal running lights on the roof. A PO had spread silicone sealant
> along the top of the windshield rubber on the outside, and I dug it out
> and used some better stuff.
> --
> Bill Van Vlack
> '76 Royale; Guemes Island, Washington; Twin bed, full (DS) side bath,
> Brazilian Redwood counter and settee tops,455, 6KW generator; new owner a/o
> mid
> November 2015; Since arrival: New HVAC blower, heat flap cable, headlight
> switch.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk
http://www.appliedgmc.com
1-800-752-7502

 

[peter bailey]

Don,t discount that the leak could be coming from the rear and running forward and the point where it leaks is the first chance for it to escape. This
can be easily diagonosed to rule out by parking the coach so that the rear is lower, then if it still leaks then it is from an intrusion at the
front.
Peter Bailey
from Ozy (Aussie)

 

[Ken B]

That is a very common leak spot right over the steering wheel. Once you have checked all of the other suggestions, take a look at the top of rubber
gasket that mounts the front windshield. There is a seam in fiber glass body at that point and many coaches do not have it ground off smoothly.

The guys that install our windshields run a full bead of sealant all the way across the top between the gasket and the fiberglass body to seal that
area. Ken D. at Preferred Glass told me that he learned that many years ago on GMCs after having to fight the leak problems over the steering wheel
on several new GMCs in the 1970's and 1980's.

They mask off the fiberglass and then fill that entire cavity all the way across and down the sides with sealant. If there ever has been silicon used
up there the sealant will not stick. So in that case there is no choice but to use a tube of black silicone.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

 

[thomas phipps]

Having just done the sealant on the windshield chore, some comments.
1. Completely remove old sealant. I used a razor knife and small flat tipped screw driver. Use your air compressor and drive out the debris and
water.
2. Mask both sides of the area to be filled with blue tape. Makes a neater line and easier clean up.
3. I used a marine grade sealant from West Marine. It is polyester and paintable. Can be applied underwater!
4. Wear plastic gloves. Stuff is sticky. Smooth material with gloved finger tip. Be prepared to change gloves.
This sealant passed our leak tent provided by mother nature yesterday. Clearance light failed this test. Bummer.
Tom, MS II
--
1975 GMC Avion
KA4CSG

 

[billvv]

Thanks, Ken and Tom.
I pulled out the old silicone along the top of the windshield gasket a couple months ago and used some of sticky marine sealant. It seems to be
sticking pretty well.

Not sure I understand the location of the seam above the windshield and its relationship to the gasket. I'm sure it would be obvious if I removed the
windshield!

I'll get up there and inspect it closely and see if I can figure it out. Not sure how water could run forward past the end of the straight section of
the coach; I've seen photos that show a mod that added drains at the end of the channel along the side which would drain any water carried forward.
Absent the drain mods, I would think the water would drop down at the end of the channel, not forward to the front cap structure.
--
Bill Van Vlack
'76 Royale; Guemes Island, Washington; Twin bed, full (DS) side bath, Brazilian Redwood counter and settee tops,455, 6KW generator; new owner a/o mid
November 2015; Since arrival: New HVAC blower, heat flap cable, headlight switch.

 

[Ken B]

The seam is in the fiberglass and is covered up by the gasket. It is directly above the steering wheel. You will not see it plainly unless you pull
the gasket down an inch or two. Obviously you can not do that with the windshield installed. Sealing all the way across the top of the gasket will
take care of the problem. If you use that marine sealant and previously had silicon up there, in a few years that sealant will loosen up. Do not
worry about it. When it happens simply re-seal it again.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

 

[Ken H.]

I fought that leak through several rounds of sealant. None of them lasted
more than a year or two for me until about 5 years ago. Then I resorted to
a rope of black butyl forced and formed into the cavity between the rubber
and the fiberglass across the top. I was not able to make a really smooth,
pretty job of it, but it's stood up well to the heat & sunshine, not
cracking and shrinking like most of the other compounds.

Ken H.