Strange Leak in Itasca 24V Class C

[Phil G.]

We have a 2005 Itasca 24V Class C that has been a fantastic little motorhome for us. However 4-5 years ago it developed a minor but frustrating irritating leak that I have tried everything to try and eliiminate. I'm wondering if anyone with a similar motorhome has experienced this:

On the passenger side at the rear corner is the largest exterior storage bay. Inside this storage bay on it's left wall (actually the rear wall of the coach) is mounted an outside showerhead, with it's short hose fed by the two water valves (hot and cold). Underneath these faucets is a small fiberglass catch basin to catch any drips of water from the valves or shower head so that the floor of the storage cabinet doesn't get wet whenever using the shower.

Whenever it rains, the leak starts. It consists of steady drops of water that are coming from somewhere within the coach's rear wall and then dripping right above the small fiberglass catch basin such that the basin eventually fills with water if it rains long enough. When the catch basin is full from the dripping water, it overflows and wets the bottom of the storage bay.

I SURE WOULD appreciate someone - who has actually had this happen in their Winnebago or Itasca Class C motorhome - fill me in on what caused it and how they fixed it. I have checked all obvious things in the rear coach wall area and the passenger sidewall area near the corner where it meets the rear wall, such - as tail light openings, running light openings, exterior ladder attach points, rear wall window, fresh water fill opening, etc..

Please help!!!

[JBP]

The only thing that I can think of is take some pictures of the area and maybe one of us can see something that you have not check. You checked all roof penetration?

[Mich F]

I'd suggest re-caulking every potential leak point, if you haven't already.

[Phil G.]

I verified the leak as coming from the same place (again) I thought it was last year ... rain water is running down the side wall and somehow entering through the fresh water port assembly and then filling the outside shower catch basin to overflowing such that the storage cabinet floor is getting soaked.

Super easy to get at, but difficult to fix ... the fresh water port assembly cannot (easily) be completely removed and I can't visually see how the water is able to penetrate through the port assembly. It seems simple, but is frustrating!

[Mich F]

I just looked at the Itasca plumbing schematics for your motor home, but having a hard time picturing what you're describing. Is there perhaps a gasket that has gone bad allowing the water to enter the compartment ? Can you cut a drain hole in an outside door so water would drain out and not fill the shower basin? It's hard (for me at least ) to make a suggestion without seeing what we're talking about.

[Phil G.]

I think I found the leak point today and attempted a repair with a plug made from butyl putty. I'll know for sure this week with the forecasted rainy weather.

I looks like water could have been entering through the opening in the fresh water filler compartment where it's closing latch finger rests in a slot in the compartment's sidewall. This slot opens into the interior right above the outside shower hot/cold knobs and catch basin. Rain water running down the outside wall of the coach can enter the fresh water compartment and then escape into the interior through this improperly sealed latch slot.

Winnebago had merely sealed this slot from leaking rain water into the interior of the storage compartment using a small soft sponge-like plug. Water could have easily saturated this small plug, since sponge isn't waterproof, and then dripped into the interior ... filling the shower catch basin and then overflowing the catch basin to soak the bottom of the storage compartment.

If this is the cause, Winnebago's design and/or construction personnel really goofed on this one. This leak has rendered this (largest in the motorhome) exterior storage cabinet about useless in rainy weather for 4 or 5 years now. It was very frustrating that I could not locate this tiny leak source ... and a coach pressure test would not have shown it up, since it was water leaking into an exterior storage cabinet that is isolated from the coach's interior.

Boy ... I hope I got it!!

[TheBarnabys]

I joined just to respond to this thread. We are the proud owners of a 2004 Itasca Spirit 24V, and I recently discovered this exact same issue with our passenger side rear storage.

When I cracked it open this past weekend I found about an inch of water in there. I never really noticed anything getting soaked while we were traveling last year (we bought the rig last summer), though I do remember that small catch basin under the outdoor shower head getting filled up with water a few times. Now it makes sense.

I scoped around inside and there wasn't any noticeable water around the rear bunk or along any interior rear walls. Then I noticed that there seemed to be some staining right below the fresh water input, just as you describe.

There really doesn't seem to be any seal or gasket between the exterior wall and this port for the fresh water. Seems like a major design flaw if I ever saw one.

I'm going to try sealing it up this week. Cheers!