Gray Tank Leaking

hikers44 · 07-12-2018, 08:04 AM

We have a 2017 Keystone Cougar that seems to be leaking from the gray tank. It is near the drain tubes that are underneath, but not leaking from the tubes. This seems to only happen when the gray tank is full or near full. It will leak through the foam there underneath, but could be coming from anywhere I guess. We had the dealer check this and they said they tried everything to make it leak, but couldn't find the problem and it didn't leak for them. This past weekend, our gray tank got full before we had a chance to dump it and there was a pretty steady drip there.

Can we remove the foam that is around the pipes to check for this, or where should we begin to find this problem? I know the easy solution is to dump when they are less than full, but that isn't always possible and we want to find and fix this leak or crack in the tank if possible. Also, since this only happens when the tank is full or near full, would that be an overflow valve or something?

Thanks!

Overspray · 07-12-2018, 08:17 AM

Mine does the same thing, and my dealer was less than hepful so far. They “tested” it again and found no leak, although at my camping trip last weekend it leaked all over. So much so that other campers noticed and inquired about it.

From what I gather, you can drop the plastic to get a leek in there with a flashlight and asses where the leak is coming from. I have to bring mine back in for them to check out some other things and hopefully they can figure out our “leak”.

**JRTJH** · 07-12-2018, 08:30 AM

The gray tank may be split on or near the top and only leak when it's full, or the vent/fill fittings may be leaking (they are also near the top of the tank). Additionally, the tank security fittings may have pierced the tank during installation or may have caused some tank damage while towing.

Dropping the coroplast underbelly so you (or your dealer) can visualize the tank. I'd guess that the only sure way to locate a source of a leak would be to "get eyes on the problem". That means, actually seeing where the source of the drip is coming from. I don't think you'll be "lucky enough" to find a leak near the top of the tank by picking out or removing the foam around the plumbing run at the bottom of the tanks/bottom of the trailer.

hikers44 · 07-12-2018, 09:27 AM

So we can just unscrew the underbelly to find the leak and then screw it back on when finished? It won't damage or void anything? Thanks!

**chuckster57** · 07-12-2018, 10:14 AM

We drop underbelly material all the time. As stated it’s the only way to determine where the leak originates. When we finish the repair, we simply put the screws back in and use expanding foam to refill what we removed.

hikers44 · 07-12-2018, 10:20 AM

Thank you all for your replies. We'll try that and see if we can find whatever the dealer can't seem to find.

Thanks!

Old Mustanger · 07-12-2018, 08:08 PM

Once you get the underbelly off so you can see, I suggest taking look at the shower trap (or whatever they are using these days). We had one that had came loose and leaked on one of our previous trailers and the water would collect on top of the material and leak out from wherever it could escape from.

Overspray · 07-13-2018, 03:50 AM

Quote:

Originally Posted by chuckster57

We drop underbelly material all the time. As stated it’s the only way to determine where the leak originates. When we finish the repair, we simply put the screws back in and use expanding foam to refill what we removed.

Any idea what type of expanding foam is used in the factory, or equivalent? (Gray/black colored stuff)

**chuckster57** · 07-13-2018, 04:32 AM

I don’t know what the factory uses, we use “great stuff” and paint to match.

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