Thursday, June 1, 2023


Gray water tank is full, valve is stuck. Now what?

Dear Dave,
The gray water lever/pull will not budge and, thus, I am unable to empty the gray water tank. (No problems with the black water tank.) Not sure of the problem, though I know it’s not the rod leading to the open/close tank valve because I checked if there was any tension on the wire as I was pulling the lever, and there was none. I also liberally added lubricant around the backside and frontside of the lever, which made no difference. Lastly, I can turn the lever so the small rod connecting to the lever rotates, but still it will not move forward and backwards. Any suggestions? Thank you. —Lawrence, 2016 Winnebago Travato 29G

Dear Lawrence,
Your valve is a remote valve that has a cable connected to the main valve back at the tank. You can find a 3D drawing and other information on the Winnebago website. Here is how the cable and valve is routed. You can find the documents here.

The gray water tanks are to the left and the valve is shown under the “ghosted” floor coming off the purple pipe. The gray water is designed to come out of the pipe through the valve to a macerating pump, which is the black box. This pumps the fluid through the blue hose to the main dump pipe. The cable snakes all the way over to underneath the toilet and then along the piping to the main dump valve harness. I assume the photo you supplied above is at the back side of the outside dump location going to the handle.

Get access to valve on gray tank

What you really need to do is get access to the actual valve on the gray tank and have someone pull the handle to watch what happens to the cable going to the valve. If the cable flexes like I believe it will, the spade valve is stuck. If it does not flex at the valve, there is a kink in the cable somewhere along the line that needs to be tracked down.

I would try dumping some valve lubrication down the shower and maybe even a little Dawn Dish Soap and let it sit for a day to see if that loosens it up. If you can get access to the valve, try lubricating that with CRC silicone. You may also be able to free it by using heavy duty channel lock pliers. If you can get to the top of the valve, drill a hole in the housing and add lubricant there.

It is not readily accessible; however, the diagram shows a few openings that might provide some access. I would suggest visiting the owner’s resource page here and either going to 3D drawings or plumbing diagrams. You could also call owner relations, who can guide you to the right documents.

 You might also enjoy this from Dave 

My gray water tank valve won’t open. Why not?

Dear Dave,
I can’t get my gray water tank to drain on my Winnebago Era 2020. The black water will drain, so I know the macerator pump is working. I took a video of the valve. It starts with the handle being in the open position. It seems like that big first black block should move but I’m not familiar with it. Thanks for the article. Hopefully, I’ll be able to winterize. I just bought the vehicle used and discovered this problem. —Ron

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Dave Solberg is a leading expert in the RV industry and the author of the “RV Handbook.”

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Dave Solberg
Dave Solberg
Dave Solberg is a leading expert in the RV industry and author of the “RV Handbook” as well as the Managing Editor of the RV Repair Club. He has been in the RV Industry since 1983 and conducts over 15 seminars at RV shows throughout the country.


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8 days ago

No problem with grey but the black tank valve seems stuck. So I same with the black valve? Will work on it. Never had an issue with the grey.

16 days ago

Engineering Genius. Design a complex system to do a simple job that is guaranteed to fail. Then bury it so it is almost impossible to diagnose and eventually repair. There must be an RV designer’s school that teaches this.

Neal Davis
16 days ago

Thank you, Dave!

16 days ago

Could they make something as basically simple as a holding tank and manual valve any more complex and hard to get to?

A lot of RV’s today seem to be designed with “hidden” valves, long cables, etc. that unnecessarily complicate a very vital part of an RV.

I’ll stick to RVs that have a wet bay with the valves readily accessible and short solid pull rods! Look for these features when buying and it may save headaches later.

Bill Byerly
16 days ago
Reply to  Spike

I agree Spike. What ever happened to the K.I.S.S. way of doing things

16 days ago

I drilled a hole Just above where the rod goes into the valve body and squirt silicone lube into it when I feel the valve getting hard to pull. To seal the hole I use a self tapping screw with a brass washer followed by a rubber washer to seal the hole. Do this with empty tanks, otherwise you will have a mess. Also after dumping the black tank I leave the valve open for a short period and let the gray soapy water flush out and help lube the seals of the black valve before closing it.

16 days ago

Plumbing is always fun.

16 days ago

Does that really help, lubricant down the shower drain?, or dawn soap! I just spray the handles rods every so often when dumping

15 days ago
Reply to  Diane

i had a gray tank valve stick and used a tip i got by pouring a little cheap vegtable oil and a gallon of water down the drain and let it sit for a little bit and then empty the tank when it loosens up. and it did loosen up

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