Foretravel Owners' Forum For owners and Fans of Foretravel Motorcoaches September 11, 2025 ...

gray water valve

October 11, 2020, 10:14:39 pm

We have a 99 U295.  Need some guidance changing the gray water valve.  It leaks when I take the cap off to drain the tanks. Thanks- Mike

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Re: gray water valve

Reply #1 – October 11, 2020, 10:47:54 pm

Electric valves or manual valves?  The answer will determine what type of replacement valve body you purchase.  New valves are available on Amazon or at most any RV parts and supply store.  Might even find them at your local Walmart.

Regardless of valve type, the replacement procedure is the same.  The valve body is mounted between two flanges with 4 bolts.

First, empty the tank.  Then, to be sure you don't make a mess, it is a good idea to tilt your coach to the side slightly to keep any remaining water from running out the drain pipe.  Then, do whatever is necessary on your coach to gain access to the valve.  Remove the 4 bolts from the valve flanges and pull them apart slightly.  Remove the old valve.  Install the new valve.  Put everything back together.

Photos in the posts linked below should help you visualize the procedure.  I was changing out both of my dump valve plus adding a 3rd valve.  If you don't already have one, this would be a great time to think about installing a 3rd dump valve.

Problems with third dump valve mod

Third Waste Gate Valve

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Re: gray water valve

Reply #2 – October 12, 2020, 12:23:40 am

I also had a leak when we first got our coach. Unfortunately it was the black water tank that leaked.
When I finally got the blade valve apart I found a piece of bone, just a splinter, keeping the blade from going all the way shut.
So I would suggest you check the slot that the gray water blade bottoms in for debris. Also, is it possible the blade handle is screwed in too far? That this is  keeping the blade from closing completely.

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Re: gray water valve

Reply #3 – October 12, 2020, 02:58:54 am

Chuck's directions are detailed and excellent.  If you are the type of person who will do most of the general maintenance on your coach then sooner or later you are going to replace the gray/black valve.  Might as well be sooner.  The second time you do it it is not a bad job at all. 

Richard

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Re: gray water valve

Reply #4 – October 12, 2020, 08:10:14 am

One thing chuck didn't mention is the need to use ABS glue on these joints.  Regular PVC glue won't give the proper fusion on the ABS pipe.  There is a combination glue that can be used, that will glue ABS, PVC or CPVC.  Just a heads up for those not familiar with the different pipe and glues.  As Richard said it's not a hard Job
Chris

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Re: gray water valve

Reply #5 – October 12, 2020, 10:09:45 am

If you are working on your waste tank valves empty the tanks as best you can, flush them out if you can and empty again.  Then when you are ready to start working on the valves tip the coach towards the opposite side of the valves.  Any leftovers in the tanks will not be dribbling out. Have plenty of rags and paper towels on hand for surprises.

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Re: gray water valve

Reply #6 – October 12, 2020, 12:02:27 pm

I just recently replaced all three of my valves, the gray water and black order with electric, and a new manual third valve. All of the above suggestions are great. Keep in mind that access inside the wet Bay is tight. Take off your watch any rings. Put on knee pads or something soft that you can kneel on. If it's dirty in there I suggest you wear a mask because you just don't know if there's any mice droppings in there until you actually get in there and look at it. Have plenty of stuff available for cleanup including a bleach base cleaning spray. The nuts and screws are small that hold them in so a small metal cup with a magnet on the bottom I find is helpful to hold the bits and bobs that come out. Take some deep breaths beforehand and again later because there will be some frustrating times trying to get your hand in there to reach the hard ones. In the end though it's not that bad just take your time.

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Re: gray water valve

Reply #7 – October 12, 2020, 12:55:17 pm

When my black tank valve handle broke, (with a full tank   ) I ended up cutting the pipe out to make room for the new valve assembly. Made the job much easier (Still a slight mess with rags packed around till the tank could drain).  I've got a write up with pics. Use search. Was back in 2016 I think.

Larry

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Re: gray water valve

Reply #8 – October 12, 2020, 09:14:54 pm

I would never just replace only the leaking valve. Replace both at the same time much easier and if one is leaking the other is probably not far behind.

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