Any suggestions to help find water leaks in a bus?

[belfert]

I was working in my bus today during a decent rain and saw several spots where small streams of water were coming in.  I just covered the windows on that side, but I could tell the water wasn't coming from my skinning job.

Any ideas how to identify where the water is coming from to fix it?

Brian Elfert

[Hi yo silver]

I've read somewhere of a pressurization approach.  This is the same approach used to test a room for integrity to contain a "total flood" Halon fire suppression system, which I've had some experience with. 
First, close windows and doors, then install a box fan or window fan in one opening, closing and sealing the opening around the fan, so that when the fan is run, it pressurizes the interior of the bus.  Then, apply a soap solution on the exterior of the bus, around roof seams and penetrations in the roof, top of windows, or windshields, near the area of the leak.  Where you see bubbles, you have a leak.  Hope this helps.
Dennis
Hi Yo Silver!

[saltmine]

Brian, you didn't say what kind of bus you have, probably doesn't make any difference. I just went thru the same problem in my MC8, '74 vintage, 94 conversion, still ongoing! I found that I had several poprivets insatlled underthe drip rails, most likely by the outfit that raised my roof. The poprivets were not sealed, so I had a bunch of 3/16 holes in my roof. Sealed them with polyureathane sealer, in the holes and all around the heads. While I was at it I sealed some suspecious looking rivets holding the cap to the roof, also around the window frames. So far. so good. We have had a rainy summer here in Alaska. Most likely not the kind of rain you get wherever you are.  PS:check the seals on your marker lites.HTH.  Saltmine, MCI8, Kenai Alaska.

[Dale MC8]

Instead of/in addition to using a soap bubble solution, use a smoke bomb inside a 'pressurized' coach to find leaks. This will find leaks that don't leak as well as the ones that do.
FWIW
Dale

[Brian Diehl]

I'll second the "check the marker light seals" as almost all my marker lights leaked when I bought the bus.

[belfert]

I haven't had a chance to check what is above the leaky area yet.  It may be the seam between the fiberglass rear cap and the aluminum roof.  I sure hope I don't have to remove all the rivets and reseal the seam there.

I did notice that Dina (or a repair shop) used a pop rivet about every 10th to 15th rivet along the roof line.  The pop rivets need to be sealed or replaced with bulb-tite rivets.

Brian Elfert

[ceieio]

Brian - I am not sure if your bus has drip rails like my MCI, but one thing you might want to check is missing or broken screws holding the drip rail on.  My MCI has so many screws in the drip rail that it must be structural!  I pulled the rails to skin my windows (ongoing) and found many heads that had popped off the screws (screw body probably kept it from leaking) but also several holes that had no screw in it al all.  Some had been caulked over, but others not.  Could be an annoying source of leaks...

Craig - MC7 Oregon

[belfert]

The drip rail on a Dina is a thin aluminum extrusion that a plastic drip rail snaps onto.  A great many of the screw heads are rusty, probably because the plastic part is missing on the one side.  I was able to order new plastic drip rails for each side.

I would remove all of the screws and reseal, but I'm afriad the screw heads would snap off.

Brian Elfert

[belfert]

I'll second the "check the marker light seals" as almost all my marker lights leaked when I bought the bus.

I looked at the upper marker lights and none of them have any gaskets.  Should I buy some rubber gasket material or just use a gasket compound?

Dina used about 1/3 pop rivets with holes and about 2/3 solid rivets along the roof line and where the caps meet the roof.  I would guess at least some of the pop rivets leak.  I can't decide if I should replace the pop rivets with bulb-tite rivets or just caulk them up good.

Brian Elfert

[DavidInWilmNC]

Hi Brian,
I'm having the same issue of leaks on my MC-8.  It's coming from somewhere above the triangle window on the driver's side.  I'm not sure if it's a clearance light, seam, or whatever.  I've sealed the lights, the seams look good, rivets and screws are sealed... I don't know.  I do know what a pain it is trying to finde these damned leaks though!

David

[Sojourner]

If you don't pressurize it….you’ll be going at it again, again, again, again and still more unknown leaks. Many places not sure leaking but reseal it and still water leaking…learn it not the one.

We at automotive dealers use this method to get every one of leak fix in one time around so you can use your time-save for other things or trip to enjoy.

All MCI aged have leaks every where that possible. So don’t waste your time trying fix one possible while next is unknown. Pressurize it either “furnace” blower or large box fan with everything closed. Either smoke bomb or water w/dishing soap & 3” brush & ladder.

It good to door & window’s seals for wind or whistling noise.

You’ll be glad you did & done & peace in mind, period.

FWIW

Sojourn for Christ, Jerry
 

[JackConrad]

I have a 102A3 that I need to test for a small water leak in the front somewhere. Where do I find these smoke bombs? Thanks, Jack

[Nick Badame Refrig/ACC]

Brian,

If you find thoose leaks, and if you are planing a paint job. Don't use silicone. The paint won't stick.

Automotive paint supply houses sell a very good product called Seam Sealer. But, If your not ready to paint,

Spray primer over the seam sealer to keep it clean until your ready.

This sealer will Not shrink, Crack, or expand like most common caulks.

Hope this helps
Nick-

[Hi yo silver]

Jack,
I have bought several pieces of test equipment from an outfit called "Professional Equipment". Their # is ...whoops, wait a minute.  I tore the # off the cover along with my address like the rest of my junk, I mean, commercial mail. HA! Laid it on the shredder, but didn't run it yet. The number is 888-334-9291.  (Here's the usual disclaimer - I have no interest in the company except as a customer..) They sell all sorts of handy test equipment for the home inspector, or in this case, the bus owner, such as a "smoke pen", powder puffer, which is cheaper, smoke matches, and something I found irreplaceable, a U.V. Laser thermometer.  There are a number of other vendors too.  If you don't have any luck, lemme know and I'll look up another source.
Dennis
Hi Yo Silver! 

[Hartley]

Smoke supplies for testing

http://testproducts.com/safecart/index.php/cPath/91?osCsid=8d24bbf7dc9bb0f80fa99f0ad9b43906

or http://www.testproducts.com

Under smoke emitters section.