Where Did This Water Come From???

[firebuild]

Hello! I have had my 91 Ford short bus for 3 years now. I got it in CA where it's relatively dry and now I am in MA where it is not dry. When I got Max (yes I am one of those goofballs with a bus name), there was some rotted out plywood on the floor next to the driver's seat, between that and where the stair tread begins, in front of the doghouse. I ripped it out and replaced it, then used thick rubber matting over it.

For 3 years I haven't thought too much about that particular area of the bus. But tonight I just got a hankering to pull up the rubber and replace it with something better looking. When I did, I found the plywood I had put in three years ago so saturated with water that the layers had separated into thin sheets. I pulled it all out easily with my hands, expecting to find a rusted out floor underneath, but the metal floor is intact, with only a few little spots of rust. There's no sign of water intrusion under the driver's seat or on the steps, only on this area in the middle of the cockpit floor, in front of the doghouse.

I thought perhaps it was coming in through the doghouse, but there is no coolant smell - this seems to be straight up water, and I don't know where that would be coming from in the doghouse. There is no evidence of water intrusion under the driver's seat or on the stairs, only in this one area in front of the doghouse, and only on that wood. With the rubber in place (I cut it from a fatigue mat), I had no clue any of this was under there.

Does anyone have any educated guesses on where this water could have come from?

[musigenesis]

I'm not sure how different your bus is from mine, but I also had severe water incursion around the driver's seat area. I suspect the windshield leaks given the amount of post-factory sealant that was applied (apparently unsuccessfully) all around it by a previous user. I've thought about using dyed water to confirm it, but that might cause problems of its own.

[firebuild]

Originally Posted by musigenesis

I'm not sure how different your bus is from mine, but I also had severe water incursion around the driver's seat area. I suspect the windshield leaks given the amount of post-factory sealant that was applied (apparently unsuccessfully) all around it by a previous user. I've thought about using dyed water to confirm it, but that might cause problems of its own.

Did you see water on the dash and seat? There is no water on the surface and there's a good 3 feet between the window and the affected area. The whole problem was completely invisible and happening underneath the rubber flooring, in the wood.

BTW, a friend eliminated her windshield leak with Flexseal.

[musigenesis]

No, the rust damage around my seat all occurred before I bought my bus, so I never saw any actual water an anything. My current parking spot has my bus angling downwards, so if the windshield is still leaking none of it is coming into the cab. Which reminded me to ask you if you had your bus parked flat all these years - if it was angled down like mine is, perhaps the leak is somewhere aft of your seat and the water is just accumulating there?

I think I will try Flexseal on my windshield eventually, at least to be proactive about it.

[firebuild]

Originally Posted by musigenesis

No, the rust damage around my seat all occurred before I bought my bus.

There's almost no rust here, which is part of my confusion.

Originally Posted by musigenesis

Which reminded me to ask you if you had your bus parked flat all these years - if it was angled down like mine is, perhaps the leak is somewhere aft of your seat and the water is just accumulating there?

My usual parking spot is level from front to back but angles down toward the passenger seat, so it's definitely possible water coming in near the driver's seat could be pooling there. But the fact that the wood in the same spot was rotted out when I got the bus makes me think this problem existed before I even took possession of it, and it seems unlikely to have had the same parking setup then.

[peteg59]

It's quite possible there is water intrusion from the "doghouse" that is causing the moisture buildup.
The leakage would not be noticed from parking, but more likely from air and water "pressure" from wet roadways spraying the area on your journeys.

Is the rubber seal/gasket in good condition?
If it is the original factory seal, it could be in need of replacement due to fatigue from age?

You could experiment by temporarily sealing the groove in the gasket where the doghouse comes in direct contact, with RTV and clamping or bolting the doghouse cover back in place for a few weeks/months to see if the area is still getting wet under the rubber mat.

Not sure if that seal is still available new, but it shouldn't be too much $$ if it is.
Good luck, and post up the fix you find for the elusive leak...

[firebuild]

Originally Posted by peteg59

It's quite possible there is water intrusion from the "doghouse" that is causing the moisture buildup.
The leakage would not be noticed from parking, but more likely from air and water "pressure" from wet roadways spraying the area on your journeys.
.

It's really looking to me like the doghouse is the "source" but I can't fully check at the moment because one of the bolts is torqued down so hard it broke my socket when I tried to remove it! The gasket looks fine but I think replacing it is probably a goos idea. I'll let you know what I end up finding. Thanks!

[musigenesis]

Originally Posted by firebuild

It's really looking to me like the doghouse is the "source" but I can't fully check at the moment because one of the bolts is torqued down so hard it broke my socket when I tried to remove it! The gasket looks fine but I think replacing it is probably a goos idea. I'll let you know what I end up finding. Thanks!

One thing to be careful of with the doghouse bolts: you may not be able to get all of them back in (especially if you're having trouble getting them out in the first place). I undid mine to replace the cab floor plywood that went under the thing, and thanks to swelling from corrosion they won't go back into the threaded holes, even after de-rusting. I'm going to have to re-tap the holes at some point, but right now my doghouse is only held in place by the screws that go into the sheet metal floor.

[firebuild]

I was finally able to get the doghouse off and the gasket is a total mess, full of debris and bent out of shape. I cleaned it out as best I could and replaced it. Now I'm going to look for a replacement, but I'm not sure I'll be successful in that.