Sealing Windshield Leaks - The 1947 - Present Chevrolet & GMC Truck Message Board Network

HeavyK20 · 10-05-2003, 11:35 PM

Will a new gasket fix a windshield leak, or is there additional measures that should be taken?

Longhorn Man · 10-05-2003, 11:37 PM

It *should*...
or it *could*...
or it *might*...

You'll have to look for rust under the gasket, and repair any you find, but even then, many of them leak with new seals, and many more leak after a year or two of wearing the new seal.

HeavyK20 · 10-05-2003, 11:58 PM

So, should I glue the new gasket in with silicone? and then lift up the lip of the gasket after the glass is in and add more silicone?

Longhorn Man · 10-06-2003, 12:01 AM

I don't know enough to answer that myself...some on here say that doing so will cause rust, but I am kinda unsure about that. I have used sillicone on beaters in the past and had no rust form there, but I may have gotten lucky on a brand or something.

crazy longhorn · 10-06-2003, 12:01 AM

If you use anything to "glue " the seal, dont use silicon....use urathane. It will be a bear to remove next time tho... crazyL

BobbyK · 10-06-2003, 03:00 AM

3M makes some great stuff.I got it at my local autobody supply store.

68LSS1 · 10-06-2003, 03:34 AM

Mine was leaking about 2 inches in, on the bottom, on each side. When I pulled the window I found that it was rusting out there. That is where a few seams come together. POR-15 makes some stuff that would work to fix it (with the window removed). It's called POR Epoxy Putty and POR Patch.

HeavyK20 · 10-06-2003, 08:11 AM

Is the urethane adhesive similar to the stuff used on modern day windshields?

**truckster** · 10-06-2003, 09:25 AM

Definitely don't use silicone. You can use urethane (it's what modern windshields are installed with), but it's a very high strength adhesive, and you may not be able to replace your windshield again without buying a new gasket. The best thing to use is 3M windshield sealer, which is a liquid butyl rubber sealant. That's what was originally used on the rubber-gasketed auto glass.
If you do take the windshield out, you should definitely fix any rust. It's hard to fix a leak if the metal's rusted.

HeavyK20 · 10-06-2003, 10:23 AM

What's the deal with silicone? Does it trap moisture or something?

bobs409 · 10-06-2003, 01:57 PM

I've heard silicone against metal will make it rust. I've never seen it myself but supposedly it does.

68LSS1 · 10-06-2003, 03:36 PM

Not only that try tp paint something that has had silicone on it. Nothing removes it. Thinner, MEK, nothing. Usually have to prime, sand, prime, sand, prime until the fish eyes stop. This is more with the silicone sprays used as lubricants though.

**truckster** · 10-06-2003, 08:17 PM

Silicone also rarely provides a permanent fix for a leak. Since it flexes after it cures, it can break loose from the glass or gasket, and then it's even harder to seal.

HeavyK20 · 10-06-2003, 10:26 PM

Thanks for the info. Just one more Q.

When it comes to buying a new gasket are any better quality than others, or is everyone carrying about the same stuff?

Longhorn Man · 10-08-2003, 10:48 PM

TTT, some one able to answer the gasket Q? I may be looking for a replacement soon.

BobbyK · 10-09-2003, 05:22 AM

I got mine from GMC Pauls.Great fit and good quality rubber.

Huck · 10-09-2003, 08:50 AM

I asked the same question re. windshield gasket quality a while back without a good answer. Here's the problem. Most of the stuff the dealers get today is overseas junk. Sometimes it's OK and sometimes it fails in a year or two. I've bought windshield rubber that was too big and the dealer told me it was made that way on purpose to allow for shrinkage!!!! In another case it was too small and in fact did shrink leaving openings where there were none the year before.
These trucks must have leaked when new as the dash has holes drilled to allow for drainage in the corners!!! Soff seal makes a gasket with a lifetime guarantee-$65.or so--of course if it leaks and you paid someone to install it, you can get a new one -assuming you can get the old one out without ripping it in the process--maybe?? They can be a bear to install especially if you have the delux model with the stainless trim. So "what to do" you say----choices:
Get one from any dealer and take your chances--about $40.+ship
Get one from Soff Seal for about $65.+ship and take your chances
Have a glass place get one that they guarantee--pay them and hopefully get a guarantee for leakage and parts replacement--lifetime. Most glass places will not guarantee their labor and your old windshield if they replace the gasket as they broke a windshield on my truck in the process and ruined the gasket as well.
Get Glass Coverage from you insurance company and then~~~~
Scratch you head like I am doing trying to figure out what to do

In any case, if you remove a windshield make sure you do a real quality job of rust removal and frame prep before the installation of a new one. POR15 paint, + their gooey patch stuff works well.
Then, after the job is done, you may as well get some of that 3M Urethene stuff just in case!!!!!!!!!

*72longbed* · 10-09-2003, 12:20 PM

Just did a new windshield and gasket 3 weeks ago. I used a Steele Co. gasket, (deluxe model), and even the installers commented on the quality of it. Very heavy duty quality rubber compared to any others that I have handled.

Just my .02

72

HeavyK20 · 10-09-2003, 03:35 PM

Where did you buy the Steele Co. gasket?

*72longbed* · 10-09-2003, 03:41 PM

I got it at the Carlisle, Pa truck show a few months ago. The have a web site, just search for: Steele Rubber Products.

72

10-05-2003, 11:35 PM	#1
HeavyK20 Registered User Join Date: Dec 2001 Location: New Richmond, WI Posts: 547	Sealing Windshield Leaks Will a new gasket fix a windshield leak, or is there additional measures that should be taken? __________________ Eric 1969 K20, 465/205 package

10-05-2003, 11:58 PM	#3
HeavyK20 Registered User Join Date: Dec 2001 Location: New Richmond, WI Posts: 547	So, should I glue the new gasket in with silicone? and then lift up the lip of the gasket after the glass is in and add more silicone? __________________ Eric 1969 K20, 465/205 package

10-06-2003, 12:01 AM	#5
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,402	If you use anything to "glue " the seal, dont use silicon....use urathane. It will be a bear to remove next time tho... crazyL __________________ 69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....

10-06-2003, 03:00 AM	#6
BobbyK Registered User Join Date: May 2000 Location: Petrolia,Ontario,Canada but working in Port Huron,Mi. Posts: 1,772	3M makes some great stuff.I got it at my local autobody supply store. __________________ 71 blazer,350SBC,approx.375HP,700R4,factory GM TPI.Dual electric fans,33x12.5x15 ATR on stock suspension. Petrolia,Ontario,Canada but working in Port Huron,MI. See ALL my Blazer pic's HERE

10-06-2003, 03:34 AM	#7
68LSS1 Registered User Join Date: Dec 2002 Location: Tampa Posts: 1,191	Mine was leaking about 2 inches in, on the bottom, on each side. When I pulled the window I found that it was rusting out there. That is where a few seams come together. POR-15 makes some stuff that would work to fix it (with the window removed). It's called POR Epoxy Putty and POR Patch. __________________ '68 Short Step LS1/T56, Hydratech, Fatman Fabrications Stage III, Baer, Hot Rods to Hell, US Body, S&W, etc

10-05-2003, 11:37 PM	#2
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	It should... or it could... or it might... You'll have to look for rust under the gasket, and repair any you find, but even then, many of them leak with new seals, and many more leak after a year or two of wearing the new seal.

10-06-2003, 08:11 AM	#8
HeavyK20 Registered User Join Date: Dec 2001 Location: New Richmond, WI Posts: 547	Is the urethane adhesive similar to the stuff used on modern day windshields? __________________ Eric 1969 K20, 465/205 package

10-06-2003, 09:25 AM	#9
truckster Senior Member Join Date: Jan 2001 Location: Orem, Utah Posts: 7,976	Definitely don't use silicone. You can use urethane (it's what modern windshields are installed with), but it's a very high strength adhesive, and you may not be able to replace your windshield again without buying a new gasket. The best thing to use is 3M windshield sealer, which is a liquid butyl rubber sealant. That's what was originally used on the rubber-gasketed auto glass. If you do take the windshield out, you should definitely fix any rust. It's hard to fix a leak if the metal's rusted. __________________ I have sworn upon the altar of God, eternal hostility against every form of tyranny over the mind of man. - Thomas Jefferson

10-06-2003, 10:23 AM	#10
HeavyK20 Registered User Join Date: Dec 2001 Location: New Richmond, WI Posts: 547	What's the deal with silicone? Does it trap moisture or something? __________________ Eric 1969 K20, 465/205 package

10-06-2003, 01:57 PM	#11
bobs409 1969 Custom 30 wrecker Join Date: Sep 2001 Location: Pottsville, Pa Posts: 2,611	I've heard silicone against metal will make it rust. I've never seen it myself but supposedly it does. __________________ Bob 63 Impala 283/PG/3.36 (under restoration) 66 Impala 327/PG/3.36 66 Chevelle SS 409/M22/3.55 69 Chevelle 307/PG/3.08 (future restoration) 69 C10 short stepside 454/TH350/3.73 69 Custom 30 tow truck 350/4 spd/4.10 (resto done, CRUISIN TIME!) 71 Cheyenne 20 fleetside 350/4 spd/4.10 71 Chevelle 6/PG/3.08 72 Chevelle 454/M21/4.10

10-06-2003, 03:36 PM	#12
68LSS1 Registered User Join Date: Dec 2002 Location: Tampa Posts: 1,191	Not only that try tp paint something that has had silicone on it. Nothing removes it. Thinner, MEK, nothing. Usually have to prime, sand, prime, sand, prime until the fish eyes stop. This is more with the silicone sprays used as lubricants though. __________________ '68 Short Step LS1/T56, Hydratech, Fatman Fabrications Stage III, Baer, Hot Rods to Hell, US Body, S&W, etc

10-06-2003, 08:17 PM	#13
truckster Senior Member Join Date: Jan 2001 Location: Orem, Utah Posts: 7,976	Silicone also rarely provides a permanent fix for a leak. Since it flexes after it cures, it can break loose from the glass or gasket, and then it's even harder to seal. __________________ I have sworn upon the altar of God, eternal hostility against every form of tyranny over the mind of man. - Thomas Jefferson

10-06-2003, 10:26 PM	#14
HeavyK20 Registered User Join Date: Dec 2001 Location: New Richmond, WI Posts: 547	Thanks for the info. Just one more Q. When it comes to buying a new gasket are any better quality than others, or is everyone carrying about the same stuff? __________________ Eric 1969 K20, 465/205 package

10-08-2003, 10:48 PM	#15
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	TTT, some one able to answer the gasket Q? I may be looking for a replacement soon.

10-09-2003, 05:22 AM	#16
BobbyK Registered User Join Date: May 2000 Location: Petrolia,Ontario,Canada but working in Port Huron,Mi. Posts: 1,772	I got mine from GMC Pauls.Great fit and good quality rubber. __________________ 71 blazer,350SBC,approx.375HP,700R4,factory GM TPI.Dual electric fans,33x12.5x15 ATR on stock suspension. Petrolia,Ontario,Canada but working in Port Huron,MI. See ALL my Blazer pic's HERE



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10-09-2003, 08:50 AM	#17
Huck Senior Member Join Date: Jun 2001 Location: Shelbyville, KY Posts: 3,261	I asked the same question re. windshield gasket quality a while back without a good answer. Here's the problem. Most of the stuff the dealers get today is overseas junk. Sometimes it's OK and sometimes it fails in a year or two. I've bought windshield rubber that was too big and the dealer told me it was made that way on purpose to allow for shrinkage!!!! In another case it was too small and in fact did shrink leaving openings where there were none the year before. These trucks must have leaked when new as the dash has holes drilled to allow for drainage in the corners!!! Soff seal makes a gasket with a lifetime guarantee-$65.or so--of course if it leaks and you paid someone to install it, you can get a new one -assuming you can get the old one out without ripping it in the process--maybe?? They can be a bear to install especially if you have the delux model with the stainless trim. So "what to do" you say----choices: Get one from any dealer and take your chances--about $40.+ship Get one from Soff Seal for about $65.+ship and take your chances Have a glass place get one that they guarantee--pay them and hopefully get a guarantee for leakage and parts replacement--lifetime. Most glass places will not guarantee their labor and your old windshield if they replace the gasket as they broke a windshield on my truck in the process and ruined the gasket as well. Get Glass Coverage from you insurance company and then~~~~ Scratch you head like I am doing trying to figure out what to do In any case, if you remove a windshield make sure you do a real quality job of rust removal and frame prep before the installation of a new one. POR15 paint, + their gooey patch stuff works well. Then, after the job is done, you may as well get some of that 3M Urethene stuff just in case!!!!!!!!!

10-09-2003, 12:20 PM	#18
72longbed Account Suspended Join Date: Jun 2003 Location: PA Posts: 1,411	Just did a new windshield and gasket 3 weeks ago. I used a Steele Co. gasket, (deluxe model), and even the installers commented on the quality of it. Very heavy duty quality rubber compared to any others that I have handled. Just my .02 72

10-09-2003, 03:35 PM	#19
HeavyK20 Registered User Join Date: Dec 2001 Location: New Richmond, WI Posts: 547	Where did you buy the Steele Co. gasket? __________________ Eric 1969 K20, 465/205 package

10-09-2003, 03:41 PM	#20
72longbed Account Suspended Join Date: Jun 2003 Location: PA Posts: 1,411	I got it at the Carlisle, Pa truck show a few months ago. The have a web site, just search for: Steele Rubber Products. 72

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