Bubbles forming on inside walls

[mldacres]

We have been living in RV for a year this month. 2 days ago I noticed some bubbles on one bedroom slide wall and on the slide wall by the range. I poked them with a pin and brown liquid squirted out. What could this be from? Those are the only 2 places so far.

[Loneoak]

It sounds like water intrusion to me. We have had that with two previous fifth wheels. It can be very expensive to fix, and will cause mould to form if not fixed. We now have an air test done once a year to catch possible issues before leaks occur.

[Mikendebbie]

I had to go find a floor plan of your unit (2018 3731FL) to see which walls you were talking about.

A leak in the bedroom slide walls (B or C on the pic) is most likely a window leak. You could try to caulk around the perimeter of the window frames and see if that cures the issue (easier than taking the window out and re-setting it in a new gasket).

Why there would be leak in the slide wall next to the stove (wall A in the pic) is above my pay grade. Maybe someone else will reply with a suggestion.

The pic below is a stock pic of a 3731 I found on the internet - not your unit.

[Cindy and Ray's Grand Tour]

We were in our second summer and I noticed the bubbles in the dining room slide. By then it was too late and we had almost 3K in water damage to the wall and floor. Floor was rotted out and the dining chair almost broke through the floor. Of course the extended warranty would not pay for water damage. We never noticed the floor wet so it was kind of weird.

What is an air test? Who does them? How much do they cost?

[Loneoak]

The air test is called Seal Tech. Prices vary by region, I expect. We pay $9 per foot of trailer length (Canadian).

There is machine that blows air into the trailer. It raises the air pressure slightly. Then they spray soapy water wherever there is caulking. If there are bubbles, then that indicates a compromise in the caulking. They take note of those area and touch up the caulking. It’s called preventative maintenance.

We get ours done at a local RV repair place. I’m sure a lot of places that do RV repairs have the machine.

[RMcNeal]

Just a wild guess, when we picked up our new unit, there was water on the stove and counter. Finally figured out that someone left the range hood vent open and pressure washed the unit forcing water into the vent. I doubt that's your problem, but there could be a leak around this vent causing your problem. That is the only penetration we have from the outside in that slide. Also, if you have an RV refrigerator, there should be a vent in that slide as well. I have the residential fridge.