Sealing Windshield

[SirRobyn0]

Looks like a royal PITA, and that may be a canned statement for when they do leak with a new gasket. I'm not saying you did anything wrong, Randy, but I think there has to be something more to it...

Plenty of these windshields have sealed for years/decades without any sealant. I wonder if it might be related to how the gasket is initially fitted/installed. Or maybe whether or not lube is used while installing the gasket to help it slide and fit in a more even manner.

I haven't wetted my K20 down since replacing the windshield and gasket a couple months ago, so maybe mine still leaks too??? Now I'm a little scared.

Now there's a question I can't answer for 100%, I don't recall if he used any kind of lube for the installation.

 

[DanMcG]

the service manual shows urethane on the pinch weld before gasket is installed. and on the gasket where the glass sits. some sort of primer goes on the pinch weld and glass before contact with the urethane.

Thanks Glen, I Looked in both the 78 and 85 repair manuals and you're right it did call for the sealant. Now the question is what urethane is going to give you enough time to install the glass without setting up on you to soon?
I searched for the part numbers from the 78 manual but didn't find any references.
urethane adhesive P/N 9981450
primer P/N 9985359
I'd be interested to see if anyone has any info on the adhesive. The only reason I ask is the Precision vid uses a sealant and the book calls for an adhesive.

 

[Oldmanyoungertrk]

Sika Flex 1a ..glass installers use it...sold at concrete supplier's and Home Depot sometimes also....comes in black....takes about 6 -12 hrs to set up.surface prep is important. 10oz caulking tube....$6- $8.

 

[Randy and Easton]

We had no rust, drains clear but the gasket itself on lower passenger side would leak from the actual seal. We used a Precision one piece self sealing gasket (no trim piece) . Jeff Gau at Precision said the sealant on the pinch weld and sealing glass into gasket was standard GM practice so Precision continued with the practice. We did not remove glass, just sealed inside the gasket around the base of the glass. No rain in forecast so we will try a hand held leak test to see if we got it. Was not hard, pulled back gasket and ran bead along base of glass and let gasket go back. Because of the large gap we had from body to upper exterior gasket we sealed that as well making sure drains remained clear.

 

[Randy and Easton]

Here is what Precision calls for. Fuzzy picture sorry

 

[Grumpy]

The windshield mast (the rubber portion that attached to the body) is urethaned in. The portion that the glass sits in is NEVER to have sealer of any kind on it.
When installing the windshield lace, NEVER, EVER, EVER, stretch the lace. If anything, the lace should be compressed as much as possible when installing.

If the leak is between the mast and the body, remove everything, clean it up and reinstall with correct sealer. Randy De Oreo's pic shows the best stuff - left side is what I personally have used for at least fifteen years.
If the leak is between the glass and the mast, reinstall the lace or purchase a new one and reinstall.