How to replace waste dump valve?

My '07 J has a leaky gray tank waste dump valve. The question how to replace it?

This link says you need about 2" of play to spread the pipes apart to remove the valve. I don't have that kind of pipe separation. Perhaps 1/8". The link suggest cutting the 3" pipe to get the separation needed to remove the valve. Then use a flexible coupling to reconnect the pipes. In the first photo, there's only room way in the back to cut the pipe. The gray tank is located on the other side of this wall.

Has anybody done this?

https://rvtipoftheday.com/rv-repair/how-to-replace-rv-waste-dump-valve/

https://www.youtube.com/watch?v=toD1epBKjnc

I think you would be better off with a repair kit, and not try to replace the whole thing.

if you can get the thin part out (by removing screws from both sides) my guess is a set of seals should do the trick.


if you let it freeze and the pipes have cracked from ice, it is another problem.

The issue is that I can't remove the thin part. The 4 bolts are out. Now you need to pull the two halves apart to slide the thin part out. The link I provided states the two halves need to be pulled apart 2" before the thin part slides out. I can barely separate them by 1/8". There is no play. The only solution I see is to cut the 3" pipe.

Cut the 3" wall flange half way between the wall and its female flair at the 90 elbow (Red line in photo).





Then use a mechanical coupler / 3" tube / 90 F-F elbow (male end of current elbow may not be far enough into the valve) / 3" tube back to valve.

I see. looked closer at your original link.

the tricky part is where to cut. and how.


I agree that the straight section looks like the best place.

will be a trick to cut straight with access you have. (with enough room on each side of the cut to place the seal OrioN found a nice photo)

https://www.youtube.com/watch?v=ZS7szCZrNXE

says you can cut pvc with some twisted nylon cord. not sure if it would work with the black stuffl

I would want to practice on a fresh piece from the local home depot.

That's a sharp trick to burn the pvc with a nylon string. Too bad there's no room to use that method. I will mark the cut location with tape and then use a Dremel tool to cut most of the way around the pipe. I'll then use a hacksaw blade to cut through the lower side of the pipe.

My black tank connection also requires work. Not looking forward to that. The black tank-to-valve rubber connection started leaking while in Baja. It appears the connection shifted 1/4" apart. Of course Winnebago installed the wormgear hose clamp screw at the worst possible position for me to unscrew it.

Drive long enough in Baja and everything falls apart.

Wouldn't a replacement blade valve be easier? That cassette jus in boots and you pull the damaged one out. New one would insert in the same space. I think it would be a lot easier....

https://www.amazon.com/dp/B07FDH61JD/ref=sspa_dk_detail_3?psc=1

http://www.doityourselfrv.com/repair-bad-rv-waste-dump-gate-valve/

Old Crows said:

Wouldn't a replacement blade valve be easier? That cassette jus in boots and you pull the damaged one out. New one would insert in the same space. I think it would be a lot easier....

https://www.amazon.com/dp/B07FDH61JD/ref=sspa_dk_detail_3?psc=1

Click to expand...

That is what he is trying to replace. But this is the scenario he is up against:

OrioN said:

That is what he is trying to replace. But this is the scenario he is up against:

View attachment 108206

Click to expand...

I dig it. Winkling that replacement cassette out and inserting a new one would be a PITA but it seems way easier than cutting the pipe. I'd think about MacGuyvering a come along and very gently pull that thing apart just enough to remove the old one. I'd coat that new one with a liberal coating of silicon grease an put it in.

Wondering if a replacement. Is designed with different seals to allow it to be easily replaced.

Old Crows said:

I dig it. Winkling that replacement cassette out and inserting a new one would be a PITA but it seems way easier than cutting the pipe. I'd think about MacGuyvering a come along and very gently pull that thing apart just enough to remove the old one. I'd coat that new one with a liberal coating of silicon grease an put it in.

Wondering if a replacement. Is designed with different seals to allow it to be easily replaced.

Click to expand...

I agree. Cutting the pipe would be my Very Last choice. I'm not exactly familiar with your set up but I also would investigate possibly loosening the tank or something of that nature before cutting the pipe. I personally have not replaced this valve but I've looked at replacement assemblies and they were all flat. I have read of others that used a piece of plastic on either side to hold the o tongs in place, side the valve into place, pull the plastic and install the bolts.

What kind of play would you get by removing the screws holding the pipe against the wall behind the red line in post 4? Maybe a little then loosening up the grey tank hangers could give you enough???

As another idea, can you add another valve in somewhere downstream? I have the same year View but the “H” model. The way the dump system was designed it left a little waste in the system, and after driving it would migrate down to the sewer cap. When I would remove the cap to dump the next time I’d be greeted by some unpleasant “drool”. So just before the outlet I added a third valve. Now when I remove the sewer cap its dry, I attach the hose, open the new valve and then the individual tank valves.

Gary

I don't know if this helps in this instance, but I have changed these valves before on a previous coach and I used 2 thin plastic document protector-sheets, one on each side of the valve which allowed easy placement of the valve between the pipes. I sprayed WD-40 on the plastic and the valve would slide right in. Once you have the valve positioned, those plastic sheets slide out real easy. Good luck, Larry 2014 Reyo P.

Removing the sheet metal holding the pipe in place against the wall is a possibility. I originally didn't want to go this route as the back side of the wall is all sealed up with some type of flexible sealant. At the moment it's hard to tell how much clearance there is between the pipe and the box wall. The gray tank is located on the right side of the photo, the left side goes to the box containing the dump valves.

az7000' said:

What kind of play would you get by removing the screws holding the pipe against the wall behind the red line in post 4? Maybe a little then loosening up the grey tank hangers could give you enough???

Click to expand...

I would think if you undid the clamp into the grey and cut the goop out it would be a fairly easy fix. Easier then cutting pipes that don't need to be cut. I'll be looking forward to hearing how it goes!

It turns out I have bigger issues than installing the valve. Black tank material is leaking at the rubber coupling between tank and valve. The rubber coupling has cracks. It looks like the same coupling is used for the gray tank. See gray tank photo just above.

It's not going to be easy replacing this coupling. Both dump valves may have to be removed to get the coupling on. In that case I'll have to cut the 3" gray water pipe.

Not that anyone asked...

It is only gray water. It is somewhat toxic liquid. It is not life threatening. It is not under pressure.

There are plastic repair glues/cements which should be effective.

My industrial/commercial experience with using the ss sleeved rubber joiners/couplers is that they are a simple fix and very effective. KISS comes to mind.

I'm certain you'll come to an effective repair choice. Keep us posted.

vic

The repair job wasn't as bad as I envisioned. Sawing the gray water pipe with a hacksaw was the best procedure. Installing everything was then very simple. Since I had to replace the gray tank dump valve and the black tank rubber coupling, I decided to also replace the black tank dump valve. I didn't want to go through all this again in a couple of years.

I noticed when removing the black tank rubber coupling that it was falling apart. No wonder it was leaking. The coupling is beefy in the middle, but necks down where the metal screw straps are located. I was wondering if a metal sleeve over the rubber coupling (like what was used for the gray water connection) would be better. It would be less likely to crack. I decided it's best to keep the coupling as the weak link. It's relatively easy to replace. I wouldn't want the black tank to crack instead. I can't eliminate the vibrations.




Here are the two rubber couplers. The left one attaches the 3" gray pipe. I had to remove the ridge in the middle of the coupler so that it could completely slide on the pipe. I can then slide the coupler in place once the other side of the 3" pipe is positioned.



Here is the view prior to install. The white hose is connected to an outdoor shower.



Gray water 3" pipe back together.

calbiker said:

My '07 J has a leaky gray tank waste dump valve. The question how to replace it?

This link says you need about 2" of play to spread the pipes apart to remove the valve. I don't have that kind of pipe separation. Perhaps 1/8". The link suggest cutting the 3" pipe to get the separation needed to remove the valve. Then use a flexible coupling to reconnect the pipes. In the first photo, there's only room way in the back to cut the pipe. The gray tank is located on the other side of this wall.

Has anybody done this?

https://rvtipoftheday.com/rv-repair/how-to-replace-rv-waste-dump-valve/

Click to expand...

On my Winnebago j their are two fernco fittings that you can loosen the clamp and it will give you enough room to insert the valves . It’s a little tricky to tighten a couple of the bolts but it can be done

Are these couplers RV specific or Home Depot/Lowes stock? Where exactly did you cut? Pic of the cut area? Thank you! I have a very slight, off and on, leak at the grey side.