Leak Test

[dale farley]

While at OKC I had a small water leak over my head and to the left of the driver's seat. Both times it rained, I got a few drops of water.

I decided today to use the pressure method to find the leak. I ran my 1 hp leaf blower for 30 minutes until the motor burned up. I then tried a large vacuum cleaner. I covered every seam, rivet, and possible opening within 6 feet of the leak with leak detector. Never found the leak. I know it is coming from the cavity above my head, so I sealed around my TV and placed the vacuum hose inside the cavity, and still did not find anything. I had cardboard taped to both sides (inside and outside) of the window, and I could not feel any air leaking to the outside.

I spent about 15 minutes spraying the top of the bus to get all the leak detector off and thought for sure I would cause the leak to appear inside the bus, but it never did. The only conclusion I can draw from my test, is that I didn't find my leak. Can't even get it to leak again. I don't think it is coming from my marker lights.


I was hoping to be able to report that I successfully used this leak detection method, but unfortunately I can't. Maybe I did something wrong. Maybe I am not squirting the leak detector in the right place. I am sure Paulette will be glad to know that I used a new sewer hose for this project.

[Jon Wehrenberg]

By the time you did that you could have sealed every joint and roof penetration on your bus roof with that stuff from Camping World.

http://www.campingworld.com/shopping/item/proflex-brushable-sealant/21208

For that method to work you really have to seal the bus up tight and that involves making sure all windows are sealed, the microwave vent is sealed, the dryer vent is sealed, etc. On my bus I would have to seal the leaks where air flows beneath the dash until I close the front shutters also.

I don't know if your AC units have a fresh air provision, but if they do those have to be sealed as well.

[JIM KELLER]

Dale, I had a leak in the same location. It WAS the marker lights.

[merle&louise]

Same thing with me, it was the 3 marker lights in the middle of the headband.

[dale farley]

Jim & Tuga,

If I pull the strip down that contains the spot light controls, my leak was coming at the far left of that opening. There is a hole about the size of my fist on the left side, and the drip was coming down through that hole. Is that about where yours was leaking? I only leak tested a couple of the lights. Mainly, the one on the side above the driver's window.

[JIM KELLER]

Dale, No my leak was farther forward from your location. Actually in the w/s post area but the level of the Bus probably has something to do with the water path.

[Orren Zook]

You might also try a tone generator with your ultrasonic leak tester to pinpoint trouble areas. We use a similar device to test tankers.

[dale farley]

Jim, That is what is puzzling me. Mine "appears" to be above the line of any of the lights. Water does some strange things, but I doubt that it is running uphill, so I think I can rule out the lights. Unfortunately, I don't see a good area as the likely candidate for the leak.

Orren,

I would try the tone generator, but unfortunately, I don't have one and wouldn't know exactly how to use it if I did. It does sound good though! I wish I had a good snake camera that I could place in the opening. I "might" be able to see where the water originates from.

Of course, I may do what Jon suggests and just cover every possible area. I assume before I do that I will have to scrape and clean all the existing sealer around all antennas, etc. Some of it looks pretty thick and hard, so that will be a job in itself.

[dale farley]

I watched a friend of mine at Yellowstone troubleshoot a leak last year. He dropped one end of the rig, ran water over the lowest part of the top, then he taped plastic over that area and moved a little higher. Repeated this process until the leak appeared. It took a while, but he solved the problem.

[dale farley]

I spent another 2 hours today trying to find my leak. I literally ran water and sprayed water on the whole front surface for over 2 hours and could not get it to leak again. I lowered the front and raised the front to simulate the angles that I could have been parked when it leaded before.

I am going to cover all the seams, antennas, and horn bases with sealer and hope I never have the problem again.

Jon, I have always used Dicor before; and I like it because it is self-leveling, but I may try the ProFlex you recommend this time. Much of what is on there now is about 1/4" thick, and I usually put the Dicor on that thick also. I am wondering if I can get the ProFlex to build up to a reasonable thickness since it is a brush-on?

[Jon Wehrenberg]

Dale, the Pro-Flex is a viscous liquid and before setting it flows out so the brush marks level themselves. I would say the thickness when applied would be less than 1/32".

I see no need to build it up, although with repeated applications I presume you would be able to do so.

Since it is clear I had no concerns about applying it to places such as the base of the remote controlled spotlight where the sealer might be visible from the right angle, but it is not suitable for sealing the marker lights.

I used a clear RTV silicon sealant across the top of all my marker light, extending down the sides. I did not seal the bottoms of the marker lights. I also sealed the side cargo lights to prevent water from entering the sides of the coach.