Why does my new windshield leak? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

cwilkie · 08-17-2009, 11:24 PM

I purchased a new windshield, weather stripping, and windshield trim. After getting it installed it leaks in a few places. Before it was the original glass and weather stripping without the trim. Is there a trick to getting the glass installed properly? Is there higher quality weather stripping out there? Or do I need to not use the trim? Please let me know what you guys think because every time it rains I get water all over my new interior.

JimKshortstep4x4 · 08-18-2009, 05:15 AM

Your local glass shop should be able to seal it for you. They use compressed air at the shop near me to find where the water is coming in and then use a special sealant gun to seal the leak.

The top outer edges of the seal is where I have seen most leaks on these windshields.

Jim

cdowns · 08-18-2009, 05:46 AM

i'm not understanding what you did// there are 2different gaskets one for trimone without trim// i've never seen the trim cause a leak/

/did you clean the windshield channel real good before install?did you use plenty of lube on the gasket during install to aid in seating the gasket? where exactly is the leak? have you tried reseating the gasket at suspected leak areas?

foosed · 08-18-2009, 08:49 AM

i had a new windshield put in my 72 and it also leaked so i brought it back in and they put a sealant around the whole windshield

cwilkie · 08-19-2009, 06:53 PM

I have the the weatherstrip with the groove for the trim. I cleaned the glass and rubber before it was installed. After it was installed it seemed like the rubber was too small for the glass since the rubber didn't look like it covered equal amounts on the driver side. It leaks from the bottom on the driver and passenger sides. Are there better quality weatherstripping out there? It's really frustrating.

JimKshortstep4x4 · 08-19-2009, 07:53 PM

The water will usually enter at the top outer edges and then it exits at the bottom. Trim or no trim usually does not make a difference. The Service Manual does suggest sealing the top outside corners.

I am not sure who has the best seals. I got the last one from GMC Pauls and it worked well.

Jim

**leddzepp** · 08-19-2009, 08:05 PM

I have heard that Precision makes the best windshield gaskets.

unclewatts · 08-19-2009, 10:39 PM

I don't know from personal experience, but I have read a lot of threads about this problem. What it all seems to come down to that a lot of different aftermarket companies sell really crappy windshield gaskets and the best one to buy is Precision. Hope this helps.

sellersrodshop · 08-19-2009, 10:57 PM

precision is better than some but still not anything to brag about. i went thru three precision gaskets before i got one to fit properly. the first two were too long & bunched up & the glass wouldn't go in. the third had edges that looked like they were trimmed by a guy with a bad hangover. i installed auto glass for over 20 years & if i had a choice, i always recommended steele rubber. they are little more pricey than the imported stuff, but well worth the price for the quality you will receive.

www.steelerubber.com

'68 C-20 · 08-20-2009, 09:07 PM

I don't know if this will help or not, but I had a windshield leak, or so I thought.

Two weeks ago I happen to pull the cowel off and noticed a small seam under the cowel about 3 inches below the windshield. It is part of the cab manufacturing and was sealed with a "rubber" sealent that looked like it was hand applied. The "Rubber" had shrunk and cracked. I climed under the dash with a light and sure enough I could not see daylight, but I could see a rust spot where the water was running in. I sealed it with some clear RTV and pushed it into the seam with me thumb, no more leak.

ChevLoRay · 08-20-2009, 09:13 PM

Quote:

Originally Posted by '68 C-20

I sealed it with some clear RTV and pushed it into the seam with me thumb, no more leak.

Make sure you use an automotive grade of RTV. There's an industrial grade that will cause rust to form and it will be some time down the road before you know. Trust me on this. Here's what you can expect (over time) if the RTV isn't automotive-grade. This is where the wiper motor was installed until it fell out one rainy morning. P.O. had put the RTV around the mounting bolts, thinking he was addressing water leaking into the cab. I have more pix. The damage gets worse. I'll spare you.

'68 C-20 · 08-21-2009, 09:00 AM

Quote:

Originally Posted by ChevLoRay

Make sure you use an automotive grade of RTV. There's an industrial grade that will cause rust to form and it will be some time down the road before you know. Trust me on this. Here's what you can expect (over time) if the RTV isn't automotive-grade. This is where the wiper motor was installed until it fell out one rainy morning. P.O. had put the RTV around the mounting bolts, thinking he was addressing water leaking into the cab. I have more pix. The damage gets worse. I'll spare you.

Holy Oxidization Batman! What a shame, real hard to repair too.

I have never heard or seen that before. I will have the cowel off again this fall, it easy and cheap enought to scrape out the RTV and re-apply. I used the Dow-Corning 732.

Thanks for the tip!

ChevLoRay · 08-21-2009, 10:47 AM

I have one more pix I will share. Non-automotive RTV, like the white stuff sold under the GE name (and others) was used where I worked to post operating instructions and other info onto these vertical steel columns in the buildings. Some posting were safety, some not. Anyway, we'd make an issue of getting enough on the back of the laminated sheets to be sure they'd stick. When it came time to update the info, we'd tug and pull 'em off of the columns and there was always rust behind the RTV.

Here's a pic of my firewall. P.O. used RTV to seal up what he thought was the bad spot. Problem is, he also created a dam that held any liquid that fell or thawed and now my HVAC area is toast around where the AC unit mounted. At least the gasket for the HVAC unit was good and didn't let any water accumulate behind it. I'm gonna end up with an aftermarket HVAC unit, when all is said and done.

Look and weep:

**Classic Heartbeat** · 08-21-2009, 11:26 AM

I would stay clear away from any RTV or silicone product what so ever. All silicone atracts water and will eventualy do what it has done to ChevLoRay's cab. Using the proper gaskets when installing the wiper motor (no other sealer needed) and automotive seam sealer where overlaps are is the only way to go. WES

'68 C-20 · 08-21-2009, 10:41 PM

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08-17-2009, 11:24 PM	#1
cwilkie Chance Join Date: Sep 2001 Location: Belcourt ,ND, USA Posts: 750	Why does my new windshield leak? I purchased a new windshield, weather stripping, and windshield trim. After getting it installed it leaks in a few places. Before it was the original glass and weather stripping without the trim. Is there a trick to getting the glass installed properly? Is there higher quality weather stripping out there? Or do I need to not use the trim? Please let me know what you guys think because every time it rains I get water all over my new interior. __________________ 1968 Chevrolet Stepside BB 396 w/TH400 1972 Chevrolet 3/4 Ton 4x4 BB 496 w/TH400

08-18-2009, 05:15 AM	#2
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	Re: Why does my new windshield leak? Your local glass shop should be able to seal it for you. They use compressed air at the shop near me to find where the water is coming in and then use a special sealant gun to seal the leak. The top outer edges of the seal is where I have seen most leaks on these windshields. Jim __________________ 1971 Shortbox step side 4x4, 350 sbc, 3:07 rear end 1965 Impala SS 400 sbc, Muncie rock crusher 1966 Impala SS 396 bbc, TH 400 1969 El Camino, 350 sbc, TH 350 1971 Snowplow built on a Blazer frame 1972 GMC Short bed, stepside, TH 400, 427 BBC

08-18-2009, 05:46 AM	#3
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Why does my new windshield leak? i'm not understanding what you did// there are 2different gaskets one for trimone without trim// i've never seen the trim cause a leak/ /did you clean the windshield channel real good before install?did you use plenty of lube on the gasket during install to aid in seating the gasket? where exactly is the leak? have you tried reseating the gasket at suspected leak areas? __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

08-18-2009, 08:49 AM	#4
foosed Registered User Join Date: Aug 2008 Location: Huron, sd Posts: 463	Re: Why does my new windshield leak? i had a new windshield put in my 72 and it also leaked so i brought it back in and they put a sealant around the whole windshield __________________ 1970 c/10 swb (show truck) 1972 custom/10 deluxe 4x4 (restoration pending) 2011 silverado ecsb z71 (daily driver)

08-19-2009, 06:53 PM	#5
cwilkie Chance Join Date: Sep 2001 Location: Belcourt ,ND, USA Posts: 750	Re: Why does my new windshield leak? I have the the weatherstrip with the groove for the trim. I cleaned the glass and rubber before it was installed. After it was installed it seemed like the rubber was too small for the glass since the rubber didn't look like it covered equal amounts on the driver side. It leaks from the bottom on the driver and passenger sides. Are there better quality weatherstripping out there? It's really frustrating. __________________ 1968 Chevrolet Stepside BB 396 w/TH400 1972 Chevrolet 3/4 Ton 4x4 BB 496 w/TH400

08-19-2009, 07:53 PM	#6
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	Re: Why does my new windshield leak? The water will usually enter at the top outer edges and then it exits at the bottom. Trim or no trim usually does not make a difference. The Service Manual does suggest sealing the top outside corners. I am not sure who has the best seals. I got the last one from GMC Pauls and it worked well. Jim __________________ 1971 Shortbox step side 4x4, 350 sbc, 3:07 rear end 1965 Impala SS 400 sbc, Muncie rock crusher 1966 Impala SS 396 bbc, TH 400 1969 El Camino, 350 sbc, TH 350 1971 Snowplow built on a Blazer frame 1972 GMC Short bed, stepside, TH 400, 427 BBC

08-19-2009, 08:05 PM	#7
leddzepp Moderator Join Date: May 2007 Location: Southern Cal Posts: 19,996	Re: Why does my new windshield leak? I have heard that Precision makes the best windshield gaskets. __________________ 1972 C/10 Cheyenne Super SWB. Restored, loaded, slammed. 1968 C/10 50th Anniversary LWB. Unrestored, stock, daily driver/work truck. RIP ElJay RIP 67ChevyRedneck RIP Grumpy Old Man Last edited by leddzepp; 08-19-2009 at 08:05 PM.

08-19-2009, 10:39 PM	#8
unclewatts 70 Chevrolet=Obsession Join Date: Jun 2009 Location: nice ca Posts: 1,067	Re: Why does my new windshield leak? I don't know from personal experience, but I have read a lot of threads about this problem. What it all seems to come down to that a lot of different aftermarket companies sell really crappy windshield gaskets and the best one to buy is Precision. Hope this helps. __________________ I'm Just like my truck. Old, Ugly and Grouchy. Except my truck starts easily in the morning and doesn't smoke! IT'S NOT EASY BEING GREEN! -Kermit the frog 1970 Chevrolet C-10 Longbed Stepside : 350, Muncie M20, 3.08 GM corp. positraction Forest green exterior/light green interior(Where all my money goes) 1996 Toyota Corolla (Parts runner)

08-19-2009, 10:57 PM	#9
sellersrodshop Registered User Join Date: Jul 2009 Location: Shooting Creek, NC Posts: 52	Re: Why does my new windshield leak? precision is better than some but still not anything to brag about. i went thru three precision gaskets before i got one to fit properly. the first two were too long & bunched up & the glass wouldn't go in. the third had edges that looked like they were trimmed by a guy with a bad hangover. i installed auto glass for over 20 years & if i had a choice, i always recommended steele rubber. they are little more pricey than the imported stuff, but well worth the price for the quality you will receive. www.steelerubber.com __________________ I called my stockbroker last week and asked him what I should be buying .......... he said "Canned Goods and Ammunition".

08-20-2009, 09:07 PM	#10
'68 C-20 Registered User Join Date: Jun 2007 Location: Dansville, NY Posts: 248	Re: Why does my new windshield leak? I don't know if this will help or not, but I had a windshield leak, or so I thought. Two weeks ago I happen to pull the cowel off and noticed a small seam under the cowel about 3 inches below the windshield. It is part of the cab manufacturing and was sealed with a "rubber" sealent that looked like it was hand applied. The "Rubber" had shrunk and cracked. I climed under the dash with a light and sure enough I could not see daylight, but I could see a rust spot where the water was running in. I sealed it with some clear RTV and pushed it into the seam with me thumb, no more leak. __________________ DIY body and paint work is cheap, making it look good... priceless -------------------------------------------- My Toys; ’26 Ford Model T ‘72 Triumph Spitfire 1500 '09 "The Briggs Flyer" Gettin' High.

08-21-2009, 10:47 AM	#13
ChevLoRay Old Skool Club Join Date: Jun 2001 Location: Benton, AR "The Heart of Arkansas" Posts: 10,880	Re: Why does my new windshield leak? I have one more pix I will share. Non-automotive RTV, like the white stuff sold under the GE name (and others) was used where I worked to post operating instructions and other info onto these vertical steel columns in the buildings. Some posting were safety, some not. Anyway, we'd make an issue of getting enough on the back of the laminated sheets to be sure they'd stick. When it came time to update the info, we'd tug and pull 'em off of the columns and there was always rust behind the RTV. Here's a pic of my firewall. P.O. used RTV to seal up what he thought was the bad spot. Problem is, he also created a dam that held any liquid that fell or thawed and now my HVAC area is toast around where the AC unit mounted. At least the gasket for the HVAC unit was good and didn't let any water accumulate behind it. I'm gonna end up with an aftermarket HVAC unit, when all is said and done. Look and weep: Attached Images __________________ Member Nr. 2770 '96 GMC Sportside; 4.3/SLT - Daily driven....constantly needs washed. '69 C-10 SWB; 350/TH400 - in limbo The older I get, the better I was. Last edited by ChevLoRay; 08-21-2009 at 10:51 AM.

08-21-2009, 11:26 AM	#14
Classic Heartbeat Project Junkie! Fishing Poor!! Join Date: Dec 1999 Location: Olympia,Wa. 98512 Posts: 10,770	Re: Why does my new windshield leak? I would stay clear away from any RTV or silicone product what so ever. All silicone atracts water and will eventualy do what it has done to ChevLoRay's cab. Using the proper gaskets when installing the wiper motor (no other sealer needed) and automotive seam sealer where overlaps are is the only way to go. WES __________________ On-line catolog Classic Heartbeat Pickup Parts WEHEPP@comcast.net Call us Toll Free (888) 338-2502 Like Us on Facebook No appointment necessary. 72 BB Chevy Custom Deluxe / Custom Camper 67 I-6 (Soon to be 5.7 LS1) Panel 68 BB Chevy Short Bed 72 6.0 LQ9 Short Bed Chevy 4X4 Olympia's fastest growing truck parts supplier. Olympia's home for Wayward Chevys

08-21-2009, 10:41 PM	#15
'68 C-20 Registered User Join Date: Jun 2007 Location: Dansville, NY Posts: 248	Re: Why does my new windshield leak? From Ecklers: Chevy Joint & Seam Sealer Use To Seal Body Seams Inside Trunk, Floors & Doors Works WIth Any Standard Caulking Gun Flexible & Paintable Will Not Crack Or Peel Natural Color 11 Oz. Size Item# 49-117 $9.99 ea. Attached Images __________________ DIY body and paint work is cheap, making it look good... priceless -------------------------------------------- My Toys; ’26 Ford Model T ‘72 Triumph Spitfire 1500 '09 "The Briggs Flyer" Gettin' High.



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