Sewer dump valves

[rheavn]

It was finally time to take on a maintenance issue that no one really likes. I hope my experience will help others. I read everything I could on the dump valves, as they are different than any other coach I have owned, so I had an idea of what I was going to encounter. My coach has three dump valves. Two air valves and one manual valve.

I started with the manual valve in the main water bay. I could pull the valve to the full open position, but I could not get it to seat in the closed position, so I suspected a problem. There are two screws on the top surface of the valve below the handle(if manual valve) or air cylinder(if air valve) that hold the dump valve in the housing. I tried to just pull up, but it didn't budge. I used a small rubber hammer & got it to move and was able to pull it straight up & out. Some one had used a small amount of silicone and that is probably why I couldn't just pull it out. The valve seal was "ruffled" which meant it was bad and needed to be replaced. This valve showed no evidence of maintenance.

I then went to the air dump valve in the main water bay. This is the main dump valve I use and there was silicone grease visible so it looked like it had received maintenance. Since I've been using this valve I presumed it was good. I drained the air system & disconnected the air lines. I unscrewed the two screws that hold the valve in the housing. I pulled straight up & it came right out. The seal was "ruffled" rather badly & needs to be replaced.

I then went to the air dump valve that is located in the rear of the AquaHot bay on the opposite side as the main water bay. This valve did not move when air was applied, so I knew this valve had issues. I disconnected the air lines. I unscrewed the two screws that hold the valve in the housing. I tried to pull straight up, but it didn't move. I tried the small rubber hammer & still no movement. I got a bar & set up a lever. After several attempts I got it to move & slowly was able to lever it out. It came out very hard. When it did come out there was no seal. The seal was wedged in the housing. I tried many different hooking tools, but to no avail. With a screwdriver I worked it to the bottom of the housing and over to the discharge side. All this was done in the blind and by feel as it was too tight an area to get in & look into the housing. The discharge end of the dump pipe had a 90 turn which kept me from a look from that end. After much thought I remembered a manual spring snake I bought over 40 years ago---wasn't sure I still had it. After a long search I found it. I was able to "snake" the seal out in about five minutes. The seal was badly swollen, distorted and torn. There was no signs of any maintenance.

My after job analysis is that one is better to maintain these valves a little more often, before you cause yourself BIG PROBLEMS. The seals are a $6.35 item. The one main air valve that showed signs of maintenance came out easily. If they had all come out easy I could do the entire maintenance job, even installing any needed seals, in about an hour. Obviously I have many hours invested so far.

I attached a photo of the distorted seal, the air dump valve, the area I had the problem and the spring snake I used.

Hope this is helpful.....................

[lbrachfe]

Rebuilt all three of mine with new paddles and rubber boots spliced into the spaces in the hard pipe on the two rear mounted ones.The main valve is easily accessed. You will need a good silicone in resealing or you will have leaks.Make sure the channells that receive the paddles are thoroughly clean or you will be taking everything apart again and again. Little bits of rubber from the seal on the paddles can mess up your day.

[rheavn]

Larry & Hedy,
Thanks for the heads up on thoroughly cleaning the valve housing. You just put a little silicone on the bottom surface of the valve when you put them together?

[prestadude]

I just went through a similar trial although I had to bring in some professional help to get the tank drained and cleaned (turns out the rubber seal had been installed backwards and the valve became hopelessly jammed). Since I had everything pulled apart I also ordered the rebuild kit for the air cylinder (new O rings and special lube). I am glad I took the time to rebuild the cylinder as the lube on the inside was getting old and crusty (just like me).

[lbrachfe]

Silicone to seal the housing only..Use grease or I prefer vaseline everywhere else, especially the handle and rod.

[encantotom]

i have only briefly looked at the 3 valves on mine. are they the dupree valves that you get the parts from dupree products? i guess i ought to just rebuild all 3 of mine while i am going through everything.

i have not even tried them at all. i did replace the clear hose on the passenger side to see how full the tank is....ha

tom in malaysia.

[rheavn]

Yes they are Dupree valves. I couldn't find any one else that sells parts. Parts prices do seem reasonable.

[RussWhite]

I had the darndest time getting the new rubber wedges into the plastic paddle. I'd push on one side and the other would pop out. I think in the end I kind of folder it to get one half in then forced the rest. I'm sure there is an easy way, I just never happened upon it. The Dupree website has improved a lot since I first bought parts from them. Prices are not out of line. I do find the life of the little circular seal between the fixed outlet and the removable adapter to have a short life before it develops a little drip. Put on another inexpensive seal and it's water tight again, but I am only getting a couple months per seal.
Tom - I suggest you take all three apart and renew them. I am guessing your waste tank is empty since you were able to replace the sight hose.

[rheavn]

Tim,
I had remembered reading about your experience and seeing the pictures, which made me remember the plumber using a snake. I had thoughts of having to break into the discharge pipe, but wanted to exhaust all options first. Your post helped me weigh my options.

Russ,
Wow!!!! Changing them every few months? I was hoping for checking them annually. Have you tried coating the seal with silicone grease or vasoline? There is a forum discussion on the Bluebird forum that talks of installing the new seals dry and then coating with Dow 111. I believe that the company, Dupree Products, was sold & is now owned by a Bluebird owner.

[encantotom]

howdy. if i recall there is two air powered ones and a single manual valve. does that sound right? i cant exactly run out and check and i would like to order the pieces and have them for when i get back.

should i order the seals and the cylinder rebuild kits?

either my tank is empty or plugged where the sight glass goes....i changed it without a poo bath. i do wish it had a macerator like my other one. i used that alot.

tom

[RussWhite]

Tim,

Russ,
Wow!!!! Changing them every few months? I was hoping for checking them annually. Have you tried coating the seal with silicone grease or vasoline? There is a forum discussion on the Bluebird forum that talks of installing the new seals dry and then coating with Dow 111. I believe that the company, Dupree Products, was sold & is now owned by a Bluebird owner.

Just to be clear - I am talking about the little annular seal that is in play when you connect the hose to the outlet of the valve. It is inexpensive, twenty cents or so, and is just an adhesive backed foam seal. It might be 1/8" thick, but gets compressed almost flat when you tighten up the ring that holds the adapter on. After a fairly short time it loses its ability to spring back and then a slight leak, in the form of a drop or two during dumping will be seen. I have a whole envelop full of them and just pull the old one off, remove the paper backing on the new one, and stick it on. It is really the only thing that bugs me about the Dupree connection.

[rheavn]

Russ,
You are right I did misunderstand. I thought you were talking about the seal that fits in the valve paddle.

[lbrachfe]

They are ALL the same Dupree valve. The heads on two are changed from the manual plunger to the air actuated, which is the part that came out when you removed the two top screws. you can buy the whole paddle with the rubber around it from Newell or any Bluebird or Airstream outlet. I got them from a Prevost convertor for $14 each and carry 3 spares. I replaced all my paddles last June (They just screw on to the metal rod) and they still funtion perfectly. Don't use any corrosives in your holding tank or they will disintergrate quicker.

[Bob & Peggy Standeford]

How do you know what size to order? The air ones appear smaller than the other one.
Bob & Peggy

[lbrachfe]

Russ,
You are right I did misunderstand. I thought you were talking about the seal that fits in the valve paddle.


and Me Too !

[rheavn]

Bob,
The paddle seals for the manual & the air valves are the same size.

[lbrachfe]

The valves are all the same too..It is only the heads that are obviously differentbut do attached almost the same way. Make sure you seal them up real good for no air or fluid leaks.

[encantotom]

i have two air valves and one manual.

from the dupree web site, what do i need to order?

does the cylinder rebuild kit for ten bucks have the seal as well? cant tell from their description.

if i wanted to rebuild the whole thing, should i get the cylinder rebuild kit for the two air valves, just the seals or the seals and the valve gate?

for the manual one should i get the entire valve assembly or just the seal or the seal/valve gate?

and then several spares of the seals?

thanks

tom

[Richard and Rhonda]

Ok, here's my .02

Order enough of the complete paddles to replace the ones you want. And a couple of just seals for grins. It's a pain to get a new seal into the paddle, and you run a chance of distorting the metal frame internal to the seal when installing it in the paddle.

On my air op dump valve, the paddle stem pulled out of the paddle. Uh oh. I threaded a long skinny lag bolt into the remains of the paddle to get it out. Used a mighty crude technique of heating the lag with a torch, threading it until it stopped into the plastic, withdraw and repeat till I got about an inch of it threaded. Grabbed the bolt just below the head with trusty vise grips. Then used a pry bar to unstick the paddle.

[encantotom]

$114 later, i have ordered everything i could possibly need assumming the air solenoids work.

thanks

tom

[encantotom]

i had a similar experience to steves. i rebuilt the two air cylinders and bought new paddles with the seals in them for them. i also bought the entire assembly for the manual valve (except housing) and it was a good thing that i did because it was broken.

the cylinders are easy to take apart after i had darlene go and pick me up a new snap ring pliars set....

the air powered one on the passenger side for the curb dump came out easy and then i saw there was no seal in it. a few pieces that were small came out of the bottom and the rest i got out with a super long needlenose pliars.

as far as i could see there was only about half of the rubber seal that i got out. it gave me an excuse to buy a color digital inspection camera that had a built in still and video camera. it had a 38" reach so i was able to go clear up into the tank. i was not able to see any more pieces though i did see something in the tank that i couldnt tell what it was.

btw, clean the camera probe up real good before inspecting your teeth....ha

i got them all redone and back in. the lesson i learned was after i put the cylinders back together and tried to install the first one. there i figured out that my two cylinders had different air fittings on them and were not interchangeable between sides without changing them so i just took it out.

also, i think i will just change the paddles with the seals in them next time.

one of my paddles was broken and the other was ok.

later

tom