Gray Tank Leak 2009 Sightseer 35J

[John Mo]

I think I have a gray tank leak. Check my thinking here.

I just de-winterized and I have water leaking onto the driver side rear leaf springs. I usually put some water in the fresh tank and let it sit with the water pump turned on while I check for leaks. If the water pump's not running and I don't see any water, I'm good.

The pump's not running, but I've got water dripping from the underside. I know undercarriage pics are hard to orient to. This is taken in front of the driver side rear wheels facing back. Based on the plumbing diagram and where I'm seeing water, I'm almost sure it's coming from the back bottom edge of the gray tank.

I'm going to leave it overnight with the water pump turned off and switch it on in the morning just to rule out a supply line leak.

The really bad thing is, there's not much in the tank. Should be just what I ran out of the lines when I winterized plus what I ran when I de-winterized. Seems like whatever's leaking is near the bottom of the tank, but it could be a line going into the topside of the tank too. I'd think a drain line going in would stop dripping pretty quickly after water quit going in.

This seems like really, really bad news. I think the tank's almost completely inaccessible. Any thoughts or suggestions or experience to share on this?

[creativepart]

How much water is in the fresh water tank? Have you filled it recently via the gravity fill?

[John Mo]

Originally Posted by creativepart

How much water is in the fresh water tank? Have you filled it recently via the gravity fill?

It's about 1/3 full, but it's located behind the rear axle, above the floor under the bed. There'd be a lot of wet floor between the fresh water tank and where it's coming out of the bottom if it was coming from the fresh water tank or the gravity fill lines.

[John Mo]

I think maybe figured it out and it's a false alarm. I turned the fresh water pump on this morning and it didn't even start up, so, no fresh water leak.

When I de-winterize, I leave the plug out of the hot water tank to give it a good flush because some antifreeze gets in when I winterize and I think flushing it is a good thing. A good amount of water runs out.

The hot water tank is on the passenger side, but about even with the position of the gray tank. I'm not sure of the exact path, but it seems plausible that some of the water running down the side found a way onto the chassis somewhere.

For anybody else with the same model, there are a couple of access options that I remembered after stepping away from the computer last night. There's a panel at the bottom of the shower and a return vent in the hallway that both back up to the top of the gray tank. I wouldn't want to have to work on anything in there, but it was good to be able to open it up and see that nothing was disconnected or wet.