Leaking grey water flush valve

[PAL07]

I get a steady drip from my grey water flush valve when tank has any amount of water in it and valve in closed position. My trailer is an 1989 25 ft Excella, and it appears to be getting worse with colder weather.
Am I looking at a major repair to stop this leaking, or a simple gasket replacement?

[AnnArborBob]

You will most likely need to replace the entire valve. The cost of the part is relatively trivial. The hard part (read expensive) is in accessing the valve if it is not exposed. In our trailer (a 2014 27 FB) the valve is hidden behind a metal panel that would need to be removed for the valve job. If your valve is exposed, its basically a four bolt job to replace. I am not familiar with your particular model, but if the valve is exposed it will be easy to find and replace.

[dbj216]

Oh such fun! Old dump valves wear out and the seals fail. It may be time for a replacement valve. It is just as easy to change the valve as it is to change the seal. Might as well do both of them while you're at it. My old valves were Thetford, but I changed them out to Valtera as I liked the Valtera one piece seal design better.

This is a rather big project. I replaced mine on my 86 Limited because the gray tank valve was leaking as you described. Yours may be similar. Airstream buried the valves in a big tank "pan" or "cover" to keep them warm in freezing weather. This makes the valves hard to get to.

There is likely an ABS plastic cover over the pull rods attached to the valves.

Many folks cut an access panel in the tank pan so the valves can be serviced. I'll bet some dealer shops perform this sensible operation.

Anyway, it's a bunch of labor to get the job done. The valves are not expensive at less than $20 each.

David

[TG Twinkie]

I have the same problem. I solved it by installing a Valterra valve which connects to the same point as the hose. It just twists on like the sewer hose. Then you connect the sewer hose to the valve.
Just remember to open this valve before you open the grey or black water dump valve.


Sent from my iPod touch using Airstream Forums

[texascanuk]

Mr DBJ216, From the picts it looks like the assembly is not horizontal from grey to black tanks. Is it? If it was could I pre-glue the parts on the garage floor to make sure they were all straight before getting under the trailer?

[txtwin]

I have this same problem. What are the sizes of the grey water valve? Is it 2" or 3" Looks like someone already took care of my black water valve.

[dbj216]

The tank outlets were on the same plane, or "level". The photo was due to a tilted camera. I can't shoot straight either. I glued up this manifold on my bench before bolting it up. The tricky part was measuring the length of the connectors from the valves to the sanitary T. ABS glue works quick, there is really no time for position adjustments. I marked everything, but I still had some miss alignment.

Both of my holding tank discharge ports were 3". Some campers have 1 1/2" diameter on the gray tank. With the 3" piping, it all drains faster.

This new drain manifold and Valterra slide valves have been under the trailer for 4 years now and no leaks. I probably would use ABS fittings instead of PVC as I think ABS is perfectly adequate for our trailers.

I made a similar drain manifold for my 66 Trade Wind using Valterra valves. This one I did do in ABS.

By the way, the 3" plastic piping slips into the holding tank outlets. I used a butyl "gutter seal" caulking around the pipe, and then hose clamped it tight. This is the way Airstream did it in 1986. Another crooked photo below.

David

[texascanuk]

Thanks, I was thinking after I posted that the wide angle camera will create distortion and could account for the pipes appearing out of level i.e. the center appearing closer to the camera than the edges making it look warped. I don't have much experience with gluing, but the irrigation system repairs that I've done confirms that you don't have much more than 5 seconds to get the alignment before the glue sets.

Is the white pipe a schedule 40 and the black pipe PVC? They do have different size dimensions (ID/OD) don't they? Does one work better than the other? Geeze your pics make it look simple, the hard part, as you've mentioned, is getting to it. Thanks.

[dbj216]

PVC is more rigid pipe. It might be better suited for exterior jobs. PVC can handle higher pressures. It is more expensive. The adhesive mix is different. Both PVC and ABS piping systems have the associated fittings that the pipe fits into.

Yep, laying under the jacked up trailer removing the tank cover pan is a hard job. The tank cover bolts are rusted and break off, and the tanks are supported by the pan, so they are just hanging from their pipes (drain and vent) when the pan is dropped. My gray water valve was leaking so I had to fix it. It was a big job but what else do I have to do?

It's not uncommon for a piece of debris to get stuck in the slide valves and start leaking. Many folks cut an access hatch in the tank cover so they don't have to remove the entire cover to fix a leaking valve. I think Airstream should have provided this. For example, there is an access port below the fresh water drain valve.

David

[texascanuk]

I can't add a picture right now, but I got the cover off the street side and the plumbing and valves are clearly visible. The grey water valve is more recessed to the left but the black is accessible. If I plan to convert to Valterra anyway I can saws-all the old pipes in two places, one cut inward of the Y on the grey line and one near the black water valve to remove the pipe that sticks straight out and be able to reach both of the water tank outlet clamps. I might be able to do this without dropping the pan. Comments?

[dbj216]

My ABS plastic thermoformed street side cover wasn't big enough to expose the valves and drain manifold. I had to remove the tank cover to gain access. It might be five years later Airstream changed the design to allow easier access to the drain valves.

Here is a photo of the plastic cover. It mainly covered the valve actuating rods and not much else.

I unbolted the valve halves and got the drain manifold out that way. You might be able to unbolt the valve halves and get the thing apart too.

David