2019 303RLS - Shower/bath GreyTank Will Not Drain

[Bikerteam]

While camping last week for 8 days our shower/bath grey tank was 2/3 full. When we attempted to drain (of course, successfully dumping black tank first) the grey tank the galley emptied fine, however when pulling the handle for the shower/bath grey tank dump nothing came out. I opened and closed it several times. Tested the pull force compared to the other grey tank and black tank, which felt about equal. Ended up driving about 150 miles home. When we got to storage, we hooked up to water and allowed some into both grey tanks. Galley emptied fine again, while shower/bath did nothing.

I have no idea where the tank is relative to the handle on the P1 systems, nor how to potentially identify and fix the issue. We camped the prior week and both grey tanks emptied fine.

I have a service appointment in mid November, but would like to diagnose and fix it myself if possible and avoid a potential costly repair.

[howson]

While camping last week for 8 days our shower/bath grey tank was 2/3 full. When we attempted to drain (of course, successfully dumping black tank first) the grey tank the galley emptied fine, however when pulling the handle for the shower/bath grey tank dump nothing came out. I opened and closed it several times. Tested the pull force compared to the other grey tank and black tank, which felt about equal. Ended up driving about 150 miles home. When we got to storage, we hooked up to water and allowed some into both grey tanks. Galley emptied fine again, while shower/bath did nothing.

I have no idea where the tank is relative to the handle on the P1 systems, nor how to potentially identify and fix the issue. We camped the prior week and both grey tanks emptied fine.

I have a service appointment in mid November, but would like to diagnose and fix it myself if possible and avoid a potential costly repair.

Welcome to the forum, Bikerteam. There are many fellow 303RLS owners on the forum, many with significant knowledge of the trailer's systems so I'll leave the technical response to them. (Paging Cate&Rob ...)

In the interim, I hope you'll check out the New Member's thread so you can get the most out of this forum: https://gdrvowners.com/forum/main-fo...to-new-members

Howard

[Bikerteam]

Thanks Howard, I’ll look at the New Members thread.

[Cate&Rob]

Bikerteam

Welcome to our owners technical forum.

The shower grey tank is forward of the drain connection point on the port (left) side of the trailer, oriented fore/aft. The black tank is parallel to this on the starboard (right) side. The kitchen grey runs crosswise and is located aft of the drain connection point.

The shower grey and black tanks have 3" gate valves. The kitchen grey may have a 3" valve or a 1 1/2" valve. You can tell which by how far the cable pulls. Same as the black tank or half this distance?

Why is nothing coming out the shower grey?? . . . you have already done the first "test" which is to check that the feel is the same as a gate that is opening correctly. A blockage in the tank is usually only partial, it is difficult to imagine what would be in a grey tank that would completely block a 3" opening.

I would try a back flush fitting on the drain connection with another twist-on gate valve downstream of this, so that you can get some water pressure on the downstream side of the (open) tank gate valve to try and dislodge whatever is blocking the drainage. You could drop the underbelly coroplast close to the drain point enough to see the grey tank gate and make sure that it is opening when you pull the handle. Note that the cable for this tank goes through a large loop and actually pulls the gate open from the opposite side.

Rob

[JBill9694]

I have to ask if Bikerteam is certain that the shower grey tank valve is closing all the way? Was there any discharge during filling the tank at home? Just something to check off the list of possible problems.

[Bikerteam]

Thanks for the replies. I’ll go to our storage facility in a day or 2 and possibly drop the underbelly as Rob suggested. The information Rob provided is invaluable. Thanks so much. However, removing a portion of the underbelly and looking at how the gate valve opens or not (which will be a first for me) is about the extent of my mechanical ability (observational).

John - thanks for your question; there was no discharge after putting water in both the galley and shower when we brought our 303 back and hooked up to the dump station/water at our storage facility.

on additional piece of information, not sure the relevance. During the camping trip noted above, we were at 2 parks. The first one for 3 days. Both grey tanks (and black) emptied fine. We drove about 20 miles to the 2nd park and stayed there 8 days. That is where the shower/sink grey tank became 2/3 full and when we tried to dump, not an ounce came out of this tank.

[tgodrich]

Thanks for the replies. I’ll go to our storage facility in a day or 2 and possibly drop the underbelly as Rob suggested. The information Rob provided is invaluable. Thanks so much. However, removing a portion of the underbelly and looking at how the gate valve opens or not (which will be a first for me) is about the extent of my mechanical ability (observational).

John - thanks for your question; there was no discharge after putting water in both the galley and shower when we brought our 303 back and hooked up to the dump station/water at our storage facility.

on additional piece of information, not sure the relevance. During the camping trip noted above, we were at 2 parks. The first one for 3 days. Both grey tanks (and black) emptied fine. We drove about 20 miles to the 2nd park and stayed there 8 days. That is where the shower/sink grey tank became 2/3 full and when we tried to dump, not an ounce came out of this tank.

We had some warranty work done on our gray water tank valves. The dealer found that the cut-out for the hole to the tank was inside the tank, and had moved to block the drain hole. I was not at all surprised by this finding. I had the same thing on a prior trailer. Seems when they drill the hole with a hole saw, sometimes the circle of plastic stays in the tank. A diligent technician would realize this and fish it out. Apparently not always the case.

Note that this piece of plastic can move around in the tank, so it can work at one site, and quit at the next, then work again, etc. The only real solution is to fish it out of there. You have to remove the drain valve to do that. Fishing it out can be a frustrating operation. Good luck.
Tony

[JeffC]

The first time I dumped my excess fresh water a large piece of plastic came out of it that had been left in there since the build. There is all kinds of crap left in these tanks. The suggestion of blowing some fresh water backwards into the tank from the dump valve is a good one.