water leak in rear upper cabinet and sliding door

[russ240]

I have my Interstate scheduled into the shop in two weeks to address a couple of water leaks. I was curious if anyone had had similar problems.

The first leak is in the top cabinet at the rear of the cabin, curb side. There is plastic liner in the cabinet with a hole in the "ceiling" where a wire loom comes through from the roof penetrations. The dealer already attempted a fix on this leak a couple of months ago by resealing the exterior roof penetrations. Since that did not fix it, I have done some additional experimenting. I tied a piece of paper towel around the wire loom where it comes through the ceiling. After the next rain I found the floor of the cabinet wet again, but the paper towel was completely dry ... so the water is NOT coming in through the hole in the ceiling. Tracking this one down could be a real pain. Any suggestions?

The 2nd leak should be a bit more straightforward, though I find it surprising. I have a drip at the TOP of the window on the slider door. Enough water comes in over night to soak the window blind, the door panel and puddle on the interior step. Please see the pic of the drip coming in. I am assuming the window will be removed and resealed as some others have documented in past posts.

[Skater]

Some shops have a system where they cover the camper with soapy water, then overpressure the inside of the camper, which causes bubbles to form outside the camper at what should be the source of the leak. Hopefully the place you're going has a system like that - if so, they should be able to track it down fairly quickly.

[Boxster1971]

That overpressure method may be difficult to use on a Sprinter as the vehicle ventilation system in the dash is nearly impossible to close. I've noticed on mine it always seems to let in a little fresh air when driving.

- - Mike

[gmillerok1]

Originally Posted by russ240

I have my Interstate scheduled into the shop in two weeks to address a couple of water leaks. I was curious if anyone had had similar problems.

The first leak is in the top cabinet at the rear of the cabin, curb side. There is plastic liner in the cabinet with a hole in the "ceiling" where a wire loom comes through from the roof penetrations. The dealer already attempted a fix on this leak a couple of months ago by resealing the exterior roof penetrations. Since that did not fix it, I have done some additional experimenting. I tied a piece of paper towel around the wire loom where it comes through the ceiling. After the next rain I found the floor of the cabinet wet again, but the paper towel was completely dry ... so the water is NOT coming in through the hole in the ceiling. Tracking this one down could be a real pain. Any suggestions?
//
The only roof penetrations are for a single hole for the cables and the mounting points for the antenna, awning, plumbing vent, solar panel, main vent, and air conditioner. The entry is for the antenna for the coax for the external antenna, and a power cable for the awning. They use an off the shelf flat plastic cover with a small half circle raised area for passing the cables. It is a very poor design. Then they used Caulk around it and the wires. The problem is that it is almost impossible to seal it completely because water can seep in between the wires. There only other suspect would be the holes drilled for the awning (highly suspect because of the area that is leaking) and the external antenna. I would closely inspect all the caulked points of entry carefully, including the vent tube, vent fan, and solar panel and recaulk any with Sekaflex that look suspect. That is what the dealer should have done the first time you took it in. I doubt it is the ac unit because it would likely leak directly under the unit.

//

The 2nd leak should be a bit more straightforward, though I find it surprising. I have a drip at the TOP of the window on the slider door. Enough water comes in over night to soak the window blind, the door panel and puddle on the interior step. Please see the pic of the drip coming in. I am assuming the window will be removed and resealed as some others have documented in past posts.

//
The window has a rubber gasket that goes around the entire window. Mine was not installed correctly and required replacement. Look and check the perimeter for this gasket. On my unit, I could clearly see where they missed the glass near the bend in the corner. Maybe that is the issue. The dealer will have to fix that issue if that is the case.

Good luck and let us know the culprit.

Gerald

[Skater]

Originally Posted by Boxster1971

That overpressure method may be difficult to use on a Sprinter as the vehicle ventilation system in the dash is nearly impossible to close. I've noticed on mine it always seems to let in a little fresh air when driving.

No vehicle is completely solid in the draft respect - I remember our B190 could be pretty drafty, and I know our trailer has several leaks (they're pretty obvious when you're camping in freezing weather). Whether the method would still work depends on how much air they're pumping in.

[Protagonist]

Originally Posted by russ240

After the next rain I found the floor of the cabinet wet again, but the paper towel was completely dry ... so the water is NOT coming in through the hole in the ceiling. Tracking this one down could be a real pain. Any suggestions?

There are several penetrations near the rear of the vehicle:
1 - Wiring for the power awning, which I believe is what you used the paper towel trick on.
2 - Mounting bracket for the awning. Which shouldn't leak because it attaches where the roof rails would be on a regular Sprinter, but you never know.
3 - Mounting bracket for the Wineguard rooftop antenna. Which is in the middle of the vehicle, but water could travel along the headliner over to the cabinet.
4 - Roof penetration for the antenna wire. Ditto.
5 - A window weatherstripping issue like on your sliding door, at the top of the curbside rear window. Unlikely, since it would presumably drip down the window and not into the cabinet, but I list it just to cover all bases.

[gmillerok1]

The awning power cable and external antenna use the same single point of entry. I know at least one owner that had a leak from this entry point.

Gerald

[Protagonist]

Originally Posted by gmillerok1

The awning power cable and external antenna use the same single point of entry. I know at least one owner that had a leak from this entry point.

Gerald

Thanks. When I posted my list of penetrations, it was a howling thunderstorm here, so I didn't get up on a ladder to look; I was going from (obviously faulty) memory. The more senior I get, the more senior moments I have.

[scott.semone]

I've just discovered that my front passenger seat-belt was soaking wet this morning; we've had a couple of rainy days for the past two days. The part of the seat-belt that was wet, was tucked away behind peice of trim. I haven't taken a look yet, but I'm planning on taking that peice of trim off and see what the damage is and whether or not I can recreate the leak; I'm guessing the sliding door or the awning mounting bracket?

[russ240]

My problem was with the seal where the window unit was installed in the sliding door. I'd guess your is coming from a roof penetration if it is ending up in the b-pillar. Good luck!

[Protagonist]

Originally Posted by russ240

My problem was with the seal where the window unit was installed in the sliding door. I'd guess your is coming from a roof penetration if it is ending up in the b-pillar. Good luck!

If you look closely, there is a roof seam more-or-less directly over the B-pillar. This seam has been known to rust in older-model Sprinters. My Interstate has a filler strip in that seam to prevent water from collecting there, but it only extends across the top, not down the sides of the raised roof.

[scott.semone]

As nice and as much attention to detail as AIRSTREAM puts into the interiors of their Interstates; I wish they would solve the roof penatrations issues...... It looks like a guy named Bubba, from Bubba's Roofing used a 2" paint brush to apply caulk or roofing tar on and around all of the areas where they made a roof penatration...

AIRSTREAM could use some guidance from the automotive industry, on how to install roof-racks and such without the use of a paint brush loaded with caulk..

Thank you for the suggestions... with some luck I'll be able to figure this out.. The big question will be whether or not I do the repair, or take it in under warranty repair...

[Supercatspjs]

We just had a leak too - upper cabinet wet and dripping down to vent and onto 2nd row. We don't have a lot of rain here so it was discovered after a big washing. Airstream re sealed all the caulking on top and seems to be dry!