Black tank valve replacement

cardinal96ss · 02-12-2017, 09:32 AM

Almost afraid to post this because of what I might hear but here goes. It appears as though I need to replace my black tank valve on our 2006 Montana. Because of the weather I haven’t cut into, or removed, the underbelly material to confirm my assessment, but it seems the valve will not close completely. Has anyone taken on this obviously nasty job?

**chuckster57** · 02-12-2017, 10:19 AM

Done too many to count. RINSE, RINSE, and RINSE again before starting this task. Coroplast should be fastened on the edges with screws and washers, just remove enough to get you access.

Once there, the actual job is fairly easy. You need to know what brand of valve you have, most common are Bristol and Valterra. The handle should say so you can get the parts from your local RV parts dealer. If it's a Valterra then there are two choices: Bladex or regular. If you get the bladex seals they will fit either Valterra valve, the Bristol requires the Bristol seals.

4 screws hold the valve together, and once you get it apart the seals will sit on lips on each end of the piping not the valve. CLOSE the valve BEFORE you install the seals, it will hold the seals in the correct position. I also rotate the valve before I put in the first screw to make sure it is seated right. Install the bolts in a cross pattern and then check the operation before you button the bottom back up.

**JRTJH** · 02-12-2017, 10:23 AM

The job isn't particularly difficult, so it's definitely an "owner can do it" type task. As for your description of "nasty". That really depends on what you mean by "nasty". If you're thinking "distasteful" Yup, it's surely that. But if you mean "getting extremely dirty", that's not necessarily going to occur.

If you're able to close the valve and flush the tank adequately several times, then drain completely, there's not really a lot left to 'flow all over you" making it "nasty", but it's still a very distasteful job.

So, I'd suggest not trying to change it on a cold, miserable, rainy day, but "limp through" until you can get under the RV in more "comfortable conditions". Pull the coroplast down a few inches on one side to see what you're facing. Peek in with a good flashlight, map out your territory and plan. You might find it easier to mark the area of the valve, make a 1 foot square "flap" in the coroplast rather than try to take it down from the attachment points along the frame rail. If you do make a "flap", be sure to leave the hinge along the front of the flap so you can secure it for travel with the least potential for forcing water/road grime into the cut edges.

Usually, you can access and remove the 4 mounting bolts and with a little manipulation and a bit of levering with a length of 2x4 or a crowbar, you can slip the old one out and insert the new valve without too much work. I won't mention the amount of "verbal abuse" you'll likely use, but that really depends on whether the foul language helps you physically or just mentally.....

Once done, return the flap to its original position, put a couple of plastic tie wraps at the corners, clean with alcohol and reseal with Gorilla Tape and you're done. Then it's time for a good shower and a bit of alcohol for the workers.....

Barbell · 02-12-2017, 03:12 PM

Been there; done that. Now, a year later, its leaking past the valve again, making a mess when you remove the cap to hook up the sewer hose. Instead of replacing the valve again, I got a Valtera valve and the proper flanges to mount it at the outlet end. You have to cut off the 4 lugs that the cap and the hose mount to and then glue the new valve in place. Even if the old valve is leaking, the new one will contain the mess so you can attach the hose with no problem.

**JRTJH** · 02-12-2017, 04:01 PM

There's no need to alter your current setup to install an additional valve on the terminal end of your discharge plumbing. Valterra sells a "twist on valve assembly" that simply replaces the cap, then you put the cap on the other side of the Valterra valve. Here's one link. https://www.amazon.com/Valterra-T58-...ra+waste+valve

Many of us have installed this valve as "insurance" against a leaking valve in the "bowels of the RV".....

kksfish · 02-12-2017, 04:03 PM

Not sure if you have tried any other fixes yet but it sounds like the problem is likely that "stuff" has built up in the slide part of the valve keeping it from closing completely. What I was able to do was pour in a couple of quarts of mineral oil and a full bottle of dawn and let it soak for a few weeks and then drive and slosh it all around with a few gallons of water. This cleaned and lubricated everything and it works better than new now! I also dump in some oil now whenever the unit will be parked for any length of time. I also put in the dawn dishwashing detergent and some water in between trips.

PARAPTOR · 02-12-2017, 08:15 PM

Something else to consider, had two issues with tank valves, one black and other gray. In both cases thought it was the valve, nope it was the cable. So I would suggest you lower the under belly cover near the pull handles.and check the connection of the cable and make it is connected properly to the handle assembly.if faulty you will still need to get to the valve to replace the cable only

For the black tank valve the outer braid of the cable had unwound about an inch. So you were loosing an inch of throw. Not closing the valve all the way.. On the gray that braid that is normally crimped to the handle assembly was sliding out and finally the. outer braid disconnected from the handle assembly.. in both cases changing the cable fixed the problem.

cardinal96ss · 02-13-2017, 07:35 AM

Wow. Thanks all. These are great suggestions. I intend to conduct all the checks then make all the changes recommended. But even though the winter has not been harsh so far, I'm going to let spring get a little closer here in Nebraska first.

PARAPTOR · 02-18-2017, 01:20 PM

Okay finally warm today to get into rig. Here are pictures of the two cable which failed and not the actual valve itself. The first picture shows the black tank cable where the outer braided actually unwound. Just enough to reduce the actual travel of the inter cable, thereby not closing the valve all the way. So do not assume it is the actual valve. Easy to check.

The second picture shows the cable from my Gray tank. On this one the cable actually started slipping out of the sleeve and eventually came all the way out. As you can see at the end I used vise grips to clamp it in there as a temporary fix.

In both cases the actual valves were fine, just replaced the cables. Good thing is now I have two extra handles when mine break

14george · 02-18-2017, 08:11 PM

At least it's a easy fix

PARAPTOR · 02-18-2017, 08:53 PM

Yes, better than changing the entire valve, but still a pain having to drop the belly cover and getting to the actual valve to connect the cable.

Failed to mention in my other posts that in each case I was saved because I had purchased the spin on valve identified in a previous post. In my eyes it is a must have in the event one of the main valves fail

Skippy38 · 05-19-2021, 07:15 AM

Quote:

Originally Posted by JRTJH

There's no need to alter your current setup to install an additional valve on the terminal end of your discharge plumbing. Valterra sells a "twist on valve assembly" that simply replaces the cap, then you put the cap on the other side of the Valterra valve. Here's one link. https://www.amazon.com/Valterra-T58-...ra+waste+valve

Many of us have installed this valve as "insurance" against a leaking valve in the "bowels of the RV".....

Late response but here goes. I am having the same problem and got the Camco Waste Valve with the sight glass on the back of it to go on the end of the pipe. Makes a great seal but I know the valve is still bad. So what I do is using the Camco waste valve I leave it closed and open the grey tank letting the main drain pipe fill up to the black tank valve to keep the "liquids" from leaking out of the black tank and forming the dreaded poo pyramid. Seems to be working so far...

LaurieStiew · 07-16-2022, 06:29 AM

I have a 2014 Laredo 5th wheel. There is a metal pipe (looks like it has electrical lines going through it) that runs right along the pull handles. So I can’t drop the underbelly. How far back should I cut an access flap to find where the cables attach to the valve?

**chuckster57** · 07-16-2022, 07:50 AM

Welcome to the forum

That is black pipe for propane. It should have P clamps holding it up and you can remove those screws, allowing to to hang. I have done this numerous times.

bustersdaddy · 09-12-2022, 05:35 AM

All well and good, but what if you can't separate the pipe enough to remove the old valve. The valves are installed with zero clearance between the tanks
Is there a trick to spread the piping?
Thanks in advance

**chuckster57** · 09-12-2022, 06:38 AM

Quote:

Originally Posted by bustersdaddy

All well and good, but what if you can't separate the pipe enough to remove the old valve. The valves are installed with zero clearance between the tanks
Is there a trick to spread the piping?
Thanks in advance

I have used pry bars, a second person and 4 feet.

Carl n Susan · 09-12-2022, 10:18 AM

Quote:

Originally Posted by bustersdaddy

All well and good, but what if you can't separate the pipe enough to remove the old valve. The valves are installed with zero clearance between the tanks
Is there a trick to spread the piping?
Thanks in advance

Cut about 1/2" out of the drain pipe which allows you room to remove/replace the valve. Use a No-Hub connector to covert he gap when you assemble it back together.

dutchmensport · 09-12-2022, 12:23 PM

Quote:

Originally Posted by bustersdaddy

...The valves are installed with zero clearance between the tanks
Is there a trick to spread the piping?
Thanks in advance

As stated above, cut about a half inch off a section of the pipe, and then you can simply slip one of these in the gap. I just did this about 3 weeks ago. It worked great! My problem was with the grey tank. Doing it this way, I didn't have to disturb the 4 inch pipe coming from the black tank that joined to one discharge outlet. It was not all that EASY as others have stated. It was a challenge. But, it WAS very doable and absolutely did not have to hire anyone to do it for me.

Click here.

**chuckster57** · 09-12-2022, 02:10 PM

I have used that a couple of times, but only after my boss looked at the job and said yes.

Jim2366 · 10-31-2022, 08:04 PM

The blank tank valve got worse and worse. When I open the cap I placed a 5 gallon bucked under the pipe. Last time it filled it with two gallons. I emptied the tank and rinsed it out for an hour. Tomorrow I have an appointment to get the valve replaced. Traveled 4000 miles in the last 6 weeks and no other problems. Very happy.

You may also like: