Replacing Black Tank Valve

I noticed on our last outing that the handle on the black tank valve was getting difficult to pull open. I was afraid if I didn't get it fixed, and it stuck in the closed position, I'd be in a major jam when we leave again in a few days. Now, I'm the first to admit that I'm no "Mr. Fix-it" kind of guy. I'm the one who usually calls a service man and helps him pay off his new truck, or send his kid to college. I read posts from people like Old Biscuit and Turtle-n-Peeps and many others on this forum and I'm just amazed, as well as a little envious, how much some people know.

Anyway, I looked up how to change the valve on YouTube. There were several videos available that made it looked so darned easy. I just knew it would be a breeze, and I could save probably close to a hundred bucks. I bought the valve at the local RV Center. It was the same brand as the old one, which I took as a good sign. I got started last evening at 5:15, thinking this would be a 30 minute job, at most. Well, at 8:15 DW and I are both under the trailer trying to get it placed just right. I had it in three times, bolted up and ready to go. Ran some water into the toilet, and it leaked all three times. The main problem is getting the gaskets in place, and then trying to maneuver the valve up between the two pipes with very limited room to work.

About this time my good neighbor walks over to see what we're doing. Bill is the kind of guy who can do anything. With his help, we finally managed to get it in just right. Tightened it up, turned on the water, and low and behold, no leaks.

We did manage to have a few good laughs out of the ordeal. I mean, you may as well keep a sense of humor when your hands are working in who knows what. I owe my neighbor a dinner at a nice restaurant.:)

I guess if a guy did this often enough he'd learn some little tricks to make it easier. Maybe the pipes in RV's should have a flexible joint every so often so you could push the PVC pipes apart enough to do a job like that. All in all though, it was a good experience.

Seeking Advice

18 Replies

coolbreeze01
Explorer
Jun 26, 2015
salem wrote:
Well, now I'm wishing I would have posted a question about changing valves before I tackled the job. These are some great suggestions. For some reason, we never thought of using a little Vasoline. I think that would have helped. My neighbor, Bill, mentioned if the problem ever came up again to consider using a rubber couple. I actually couldn't picture just what he meant. Thanks, Ron3rd for posting that photo. That would have been an excellent idea. And DSPD Don, that cut up milk carton trick was also something I hadn't considered. Now, if I ever get the opportunity to help someone else, I'm going to seem like such an expert. :B You guys are great. Thanks, again.

There you go...........
salem
Explorer
Jun 26, 2015
Well, now I'm wishing I would have posted a question about changing valves before I tackled the job. These are some great suggestions. For some reason, we never thought of using a little Vasoline. I think that would have helped. My neighbor, Bill, mentioned if the problem ever came up again to consider using a rubber couple. I actually couldn't picture just what he meant. Thanks, Ron3rd for posting that photo. That would have been an excellent idea. And DSPD Don, that cut up milk carton trick was also something I hadn't considered. Now, if I ever get the opportunity to help someone else, I'm going to seem like such an expert. :B You guys are great. Thanks, again.
Dtank
Explorer
Jun 26, 2015
"Salem" - been there, done that.

No fun no matter what your "skill level" is, when -

The valve is way up under the RV.
(There WAS a time when the valves were very accessible *externally* on the 3" drain pipe - as compared to cable and electric valves in use now)
There is NO room to cut pipe and add the/a "rubber coupler"..:(

Made my own "spreader".
Yeah - used the vaseline "trick".
Still a *major*, MAJOR "PITA"..:(

As a "heads up" (check first!) often the cable (or the electric motor) is the culprit and the valve is OK.

For my own peace of mind I added a basic "manual pull" valve in the exterior section of the 3" drain.
I now have the option of just leaving the "PITA" valve in the *open* position.

Lubricant/s:
Other than via the pull rod on a Valterra valve, there is no way to add lubricant to the *interior* of the valve.
(Spray & pray?)..:@

Some folks add some vegetable oil to (in) the black tank (when it's empty), add water and flush.
Does it help? Nobody will ever know for sure..:h

BTW - everyone should carry a "Valterra T58 Twist-On" valve as a temporary backup.
(About $15-20 available from Amazon & other suppliers)..:C

And of course - that requires you to get the failed valve into the *open* position. But should be lots easier than a replacement.

.
DSDP_Don
Explorer
Jun 26, 2015
If you have to do it again, it can be simple. Before you place the new valve into position, use a liberal amount of grease or Vaseline to keep the seals positioned correctly (peanut butter in an emergency). What usually gives most people a problem is that the seals get dislodged while trying to squeeze the assembly back into place. Typically, the grease will do the trick. If you're still having issues, take a cheap plastic mat (plastic milk carton in an emergency) and cut it into two pieces approximately 5" x 12". Place the mat on both sides of the valve, protecting the rubber seals. Insert the new valve into position and once lined up, pull the plastic mats out while holding the valve in place.
coolbreeze01
Explorer
Jun 26, 2015
Actually using WD-40 Specialist Silicone. Good stuff ;)
westend
Explorer
Jun 26, 2015
coolbreeze01 wrote:
So far, WD-40 keeps my valves working smoothly.
I'd suggest to change lubrication products. WD-40 is known to eat rubber and certain plastics. Silicone spray is probably a better alternative.
Ron3rd
Explorer III
Jun 26, 2015
Good job, and now you now how to do it next time. I had to replace the entire valve on my old trailer as the screws had rusted out and a couple of the "ears" where the screws go in the corners had broken off, so a complete new valve was needed and the gasket repair kit was not an option. Problem was, there was no way to get the valve off without breaking the connection into the gray tank, something I did not want to do. Someone on this forum gave me the idea to use one of those rubber couplers with clamps shown in the link below. I simply cut the pipe off with my sawzall and installed the new valve with the coupler. Made the job fairly easy. Picked the coupler up at Lowes:

RUBBER COUPLER
coolbreeze01
Explorer
Jun 26, 2015
So far, WD-40 keeps my valves working smoothly.
LadyRVer
Explorer II
Jun 26, 2015
I did one replacement, one time....had the same problem with the gasket slipping.
took me about 3-4 hours, but got 'error done!
MFL
Nomad II
Jun 26, 2015
There is a lot of satisfaction in fixing something yourself, even if it takes longer, and involves a do over. Now knowing what the job involves, it will go much easier the next time.

Taking an RV in for service, is not like taking your truck to the dealer.

Glad you were able to fix it yourself!

Jerry