Leaky@ss windows

[Rogue1bus]

I swear I’m spent a crazy amount of time unsuccessfully trying to stop window leaks... I have a 2002 Amtran RE, the water keeps appearing in the corners so of the windows. I’ve probably invested $50 worth of caulk trying to seal them up. I think a may have to caulk the insides of the bottom part of the windows, but that seems strange considering all the moisture is coming from outside... Anybody have similar problems and or advice to stop the leaks?

[bus-bro]

Did you pull the window units out to recaulk?

[Rogue1bus]

Originally Posted by bus-bro

Did you pull the window units out to recaulk?

I did a couple, but mostly scrapped and recaulked from the outside.

[bus-bro]

I'd say that in order to effect a successful long-term repair you would need to pull the window assemblies, clean and recaulk, then reinstall.

I can guarantee, providing the window assemblies themselves don't leak, that if you used 3m 5200 for a caulk they would not leak.
On the downside, you couldn't ever get those suckers out -- at least in one piece.

[Rogue1bus]

Originally Posted by bus-bro

I'd say that in order to effect a successful long-term repair you would need to pull the window assemblies, clean and recaulk, then reinstall.



I can guarantee, providing the window assemblies themselves don't leak, that if you used 3m 5200 for a caulk they would not leak.

On the downside, you couldn't ever get those suckers out -- at least in one piece.

Good plan.. I may take this approach. It’s jus really puzzling because I can SEE all the joints on the exterior and the look good...

[bus-bro]

Though I wouldn't the 3m 5200 as a caulk for the windows. Use something you can cut out. They used a butyl caulk on my '84.

[Drew Bru]

Originally Posted by Rogue1bus

I swear I’m spent a crazy amount of time unsuccessfully trying to stop window leaks... I have a 2002 Amtran RE, the water keeps appearing in the corners so of the windows. I’ve probably invested $50 worth of caulk trying to seal them up. I think a may have to caulk the insides of the bottom part of the windows, but that seems strange considering all the moisture is coming from outside... Anybody have similar problems and or advice to stop the leaks?

We had persistent leaky windows on our Amtran too. Amtran is apparently known for leaking windows. We pulled all of our windows, cleaned the metal window assembly with acetone and a wire brush (using a drill attachment) so they were spick and span clean. Those suckers looked brand new! Then we cleaned the mating surfaces on the bus itself, down to fresh paint (removed any traces of butyl tape). Then we use 3M Dynatron 550 on all mating surfaces and put them back together. This was a solid 2 days worth of work. It wasn't all that bad, truthfully. Put on some good tunes and have a partner to help ya. Having said all this.....the windows STILL leaked. Especially in the corners.


It turned out that the water was coming in at the bottom of the glass, where the rubber gasket is supposed to seal the glass-metal union. The rubber was a bit dry rotted and it let water into the metal window frame, where it travels down to the corner and to the inside of the bus. Our temporary solution was to put a strip of clear weathersealing tape at the bottom of the glass, covering that gasket. It works like a charm. Our plan is to just caulk over that gasket, but we've got many other projects ahead of that.


Bottom line? Try sealing the rubber gasket before you pull any windows....that just may be the ticket and save you lots of frustration.

[Rogue1bus]

Originally Posted by Drew Bru

We had persistent leaky windows on our Amtran too. Amtran is apparently known for leaking windows. We pulled all of our windows, cleaned the metal window assembly with acetone and a wire brush (using a drill attachment) so they were spick and span clean. Those suckers looked brand new! Then we cleaned the mating surfaces on the bus itself, down to fresh paint (removed any traces of butyl tape). Then we use 3M Dynatron 550 on all mating surfaces and put them back together. This was a solid 2 days worth of work. It wasn't all that bad, truthfully. Put on some good tunes and have a partner to help ya. Having said all this.....the windows STILL leaked. Especially in the corners.


It turned out that the water was coming in at the bottom of the glass, where the rubber gasket is supposed to seal the glass-metal union. The rubber was a bit dry rotted and it let water into the metal window frame, where it travels down to the corner and to the inside of the bus. Our temporary solution was to put a strip of clear weathersealing tape at the bottom of the glass, covering that gasket. It works like a charm. Our plan is to just caulk over that gasket, but we've got many other projects ahead of that.


Bottom line? Try sealing the rubber gasket before you pull any windows....that just may be the ticket and save you lots of frustration.

Perfect! Thank you so much! I replaced one of the windows so I had the frame out and examined it and the corner where the water pools is higher than the part of the frame where water would go if it’s entering behind the actual frame so it’s gotta be the glass seal..

[spenceronehalf]

Originally Posted by Rogue1bus

I swear I’m spent a crazy amount of time unsuccessfully trying to stop window leaks... I have a 2002 Amtran RE, the water keeps appearing in the corners so of the windows. I’ve probably invested $50 worth of caulk trying to seal them up. I think a may have to caulk the insides of the bottom part of the windows, but that seems strange considering all the moisture is coming from outside... Anybody have similar problems and or advice to stop the leaks?

Only pulling and resealing stopped my leaks

[Rogue1bus]

It was definitely underneath the glass seal. I cut the window sealant with a razor, peeled it out, and tapped it down into the seal to create a space for the new caulk to seal up things. When I tapped the old gasket down into the window water was splash out in my face.

I’m confident I found the source.. I’ll know soon enough

[Oscar1]

Originally Posted by Rogue1bus

It was definitely underneath the glass seal. I cut the window sealant with a razor, peeled it out, and tapped it down into the seal to create a space for the new caulk to seal up things. When I tapped the old gasket down into the window water was splash out in my face.

I’m confident I found the source.. I’ll know soon enough

The suspense is killing me!

[TheHubbardBus]

Originally Posted by bus-bro

Though I wouldn't the 3m 5200 as a caulk for the windows. Use something you can cut out. They used a butyl caulk on my '84.

No, absolutely not. 5200 is an adhesive sealant with the emphasis on adhesive. It creates what would be considered 'permanent' bonds. Way too strong for window frame assemblies designed to be removed. I don't think you'd be able to without destroying them.


Our International dealer told us Sikaflex 201 was what was used from the factory for sealing our bus windows, so we bought a case.

For comparison purposes, Sikaflex 201 advertises a tensile strength of 175 psi, a tensile lap-sheer strength of 130 psi, & a shore-A hardness of 38. 3M 5200 is at 705 psi, 400 psi (for aluminum, steel is even higher), & 68, respectively.


TDS for each:


https://usa.sika.com/dms/getdocument...flex201-us.pdf

https://multimedia.3m.com/mws/media/...-tech-data.pdf

[mmoore6856]

another reason we removed all the windows when we raised it. skinned over with 16 a and used camper windows with screens. school bus windows are junk

[ol trunt]

I used Silkaflex 220+ to seal up all my windows, body seams and body penetrations. It is easy to use and cleans up with mineral spirits before it hardens. When cured it remains flexible and is paintable with any paint. I also used it to install the windshield as it is an OEM glass bonding agent. I pay $10 a tube for it from a local windshield installing outfit. I am entirely satisfied with its performance.

Jack