Black Tank Valve Issue

[AmiThomas]

I am unable to close my black tank valve all the way. It closes almost all the way. I have done several clean outs, always use the appropriate chemicals and I just can’t figure it out. Anyone have any suggestions? 2021 Prime Time Tracer TT.

[loyda]

Maybe something hard was in tank from production or dealer and has worked it’s way down. Open valve and stick garden hose in through toilet to flush out

[PhilFromMaine]

I had the same problem once. I got one of those add on valves and just hooked it up-problem solved.

Last year, when staying in a permanent campground, I ran the black tank flush for about 20 minutes and it cleaned out residual toilet paper that was blocking the original valve from closing. Toilet paper was the culprit.

https://www.amazon.com/Camco-Adapter...s%2C105&sr=8-9

[5picker]

Welcome to the forum, I see it is your 1st post.

Is your black tank valve cable actuated or rod actuated?

Those with cables often have issues because the cable is often too long, binding or misrouted, not allowing the valve to close properly. Often properly routing or shortening the cable cures the issue. Lubing the cable may help.

Rod actuated valves usually don't have that issue but sometimes paper (or heaven forbid flushable wipes) can get lodged in the slot the valve blade travels in and jam up.

Either way, you'll likely need to access the valve itself to diagnose if flushing the tank well doesn't cure the problem.

[jimmarako]

Is your valve rough to operate? If so I'd try WD-40. These vales tend to bind up over time.

If your valve is just a rod with a handle open the valve fully. Spray the rod with WD-40. Close it 1/2 way. Spray the plastic piece, and the groves inside the discharge hole. Open it fully again and spray the rod and the discharge hole. Try closing fully. Repeat as needed. Basically just soak it with WD-40 until in works.

For a cable system I'd try the same method though lubing the cable might be tricky.

For ongoing maintenance I spray mine down with a "dry lube" 2-3 times a year to keep it moving easily.

Jim M.

[SacRV]

Every time we open our grey and black tank valves I spray them with a silicone based lubricant. It keeps them moving freely.

[Larry-NC]

Originally Posted by AmiThomas

I am unable to close my black tank valve all the way. It closes almost all the way. I have done several clean outs, always use the appropriate chemicals and I just can’t figure it out. Anyone have any suggestions? 2021 Prime Time Tracer TT.

Ami, this is not a very dirty job. I've done it and only washed my hands afterwards. The valve itself is sandwiched between two flanges, with four bolts holding the sandwich together. You will need a pair of 3/8" - 7/16" wrenches or sockets or even adjustable wrenches.

1. Drain the black tank. If you are not at a place where you can dump the tank, dump a few gallons into a bucket and pour it into your household toilet. Repeat until empty.
2. Remove the four bolts holding the sandwich together.
3. Pull the valve out.
4. Dip the valve in a bucket of clean water.
5. Use an old toothbrush (I always save old toothbrushes for jobs like this) to clean the grooves that the shutter slides into.
6. Clean until the valve seats completely.
7. The two rubber valve seals may have dropped out while cleaning. Put them back in place with the smaller step part facing the middle.
8. Slide the valve-with-seals back into place.
9. Place the four bolts to hold the valve in place.
10. Install the nuts and tighten until just snug.
11. Then tighten each one a half-turn at a time. (If you were to tighten one nut all the way down without the others, you might warp the flange and break a corner off.)
12. When they are all tight (about as tight as when you loosened them, you are done).

When finished, you will probably agree that this job was really no worse than changing a diaper. (That's not sexist--I've changed my share. )

[CliffArthur]

Larry, how is the valve assembly accessed??
Lever moves very hard, was sprayed with WD40!!
The tank froze when it was so cold before Christmas!!
It worked before!!
Owner is very conscientious about emptying tank!!

[Larry-NC]

Originally Posted by CliffArthur

Larry, how is the valve assembly accessed??
Lever moves very hard, was sprayed with WD40!!
The tank froze when it was so cold before Christmas!!
It worked before!!
Owner is very conscientious about emptying tank!!

The valve assembly is right behind the cap that is removed when emptying the tank. Usually they are quite visible.

Some RVs have a sheet of corrugated plastic covering the bottom. If your valve is above this, you will have to cut an access hatch and work through it. Cut three sides, leaving the front side uncut. Fold the flap down to work. When done, put it back up using good tape (not duct tape).

Attached is a picture of a typical black tank valve which I labelled.

[FirstFiver]

My cable valve never worked properly and finally I decided to change the valve. It was the same issue. Never closing completely.

It was a royal PITA to access and my black tank was in the middle of two grey tanks.
I had to wedge the two sides of the flanges to slip the old valve out and the new one in.
It turned out the factory had gobbed the glue on the flange and the excess glue built up on the valve edge. So when closing the valve it would almost close but stop because it hit the glob of glue.

[Larry-NC]

Originally Posted by FirstFiver

My cable valve never worked properly and finally I decided to change the valve. It was the same issue. Never closing completely.

It was a royal PITA to access and my black tank was in the middle of two grey tanks.
I had to wedge the two sides of the flanges to slip the old valve out and the new one in.
It turned out the factory had gobbed the glue on the flange and the excess glue built up on the valve edge. So when closing the valve it would almost close but stop because it hit the glob of glue.

Often the sandwich is tight and you have to spread the two flanges a bit. I've done this alone, but I can imagine a situation when it would be easier with two people.

Good job finding the cause and fixing it.

Even with the hiccups you encountered, you were probably done in two hours, right?

[FirstFiver]

Yeah, it was a couple hours.
If it had been either of the grey tanks, it would have been a lot easier since they would have been at either end of the drain pipe runs.
That would have made spreading the flanges easier. With it in the middle, the drain line was tight together.

In hindsight I should have just bought all three valves, taken them all out at once. I probably could have changed all three in the time it took to change the one black tank valve.

[Chuck_S]

A black tank valve is $25 and can be replaced in 15 minutes. Not worth the trouble shooting or cleaning efforts.

-- Chuck

[Larry-NC]

Originally Posted by FirstFiver

Yeah, it was a couple hours.
If it had been either of the grey tanks, it would have been a lot easier since they would have been at either end of the drain pipe runs.
That would have made spreading the flanges easier. With it in the middle, the drain line was tight together.

In hindsight I should have just bought all three valves, taken them all out at once. I probably could have changed all three in the time it took to change the one black tank valve.

There's no need to replace the valves, or even the seals unless you know there's a problem. You can generally reassemble with the old parts. You might have even been able to just loosen the screws on the other two valves to get some slack, without fully disassembling.

Wondering why Ami hasn't come back to tell us how she's done.

[aceinspp]

If you have the cable type the wire can get bent by pushing in to hard. You may have extra length of cable and one thinks its not totally closed and you continue till you bend the cable. Then the valve will not totally close. Ask me how I know had to have mine replaced and I made sure that they shorten the cable some to the handle almost touches panel. Later RJD

[NMWildcat]

Originally Posted by Chuck_S

A black tank valve is $25 and can be replaced in 15 minutes. Not worth the trouble shooting or cleaning efforts.

-- Chuck

Not always true. If you have a model with exposed valves and a rod instead of cable, maybe. With one exception, every towable RV I have owned has had valves far from the exit point, uses cables, and is above the bottom covering and embedded in insulation.
I have replaced/cleaned valves and/or re-routed valve cables correctly, which included dropping the bottom coroplast, tracing the cable to find the valve, and then fixing problem and replace insulation and coroplast. Not a 15 minute job

[5picker]

Originally Posted by NMWildcat

Not always true. If you have a model with exposed valves and a rod instead of cable, maybe. With one exception, every towable RV I have owned has had valves far from the exit point, uses cables, and is above the bottom covering and embedded in insulation.
I have replaced/cleaned valves and/or re-routed valve cables correctly, which included dropping the bottom coroplast, tracing the cable to find the valve, and then fixing problem and replace insulation and coroplast. Not a 15 minute job

X2
Not all drain valves are located and actuated the same.

I'd have to say of the 15+ R/Vs I've had over the years, the photo in post # 9 is the exception rather than the norm.

Many valves are now up in the belly where "arctic package" heat supposedly keeps them from freezing. They are often actuated by misrouted, mis-length cables and are problematic even when new. Even rod actuated valves can be up inside the coroplast as my last Flagstaff were. It took a half hour just to be able to see them.

Many folks think every R/V is like theirs and a 15 minute job on what they have, could be much, much different/longer on someone else's R/V.

[FirstFiver]

Originally Posted by Larry-NC

There's no need to replace the valves, or even the seals unless you know there's a problem. You can generally reassemble with the old parts. You might have even been able to just loosen the screws on the other two valves to get some slack, without fully disassembling.

Wondering why Ami hasn't come back to tell us how she's done.

I have the luck where if I don't it is guaranteed to break later.
My galley tank has a leak so I need to get back under there again to see if it can be patched or if I need a new tank. RecPro has the tank listed but it is out of stock with an unknown date for being back in stock.

I am going to order the other valves and change them when I fix the tank.

[johnandval]

Originally Posted by Larry-NC

Ami, this is not a very dirty job. I've done it and only washed my hands afterwards. The valve itself is sandwiched between two flanges, with four bolts holding the sandwich together. You will need a pair of 3/8" - 7/16" wrenches or sockets or even adjustable wrenches.

1. Drain the black tank. If you are not at a place where you can dump the tank, dump a few gallons into a bucket and pour it into your household toilet. Repeat until empty.
2. Remove the four bolts holding the sandwich together.
3. Pull the valve out.
4. Dip the valve in a bucket of clean water.
5. Use an old toothbrush (I always save old toothbrushes for jobs like this) to clean the grooves that the shutter slides into.
6. Clean until the valve seats completely.
7. The two rubber valve seals may have dropped out while cleaning. Put them back in place with the smaller step part facing the middle.
8. Slide the valve-with-seals back into place.
9. Place the four bolts to hold the valve in place.
10. Install the nuts and tighten until just snug.
11. Then tighten each one a half-turn at a time. (If you were to tighten one nut all the way down without the others, you might warp the flange and break a corner off.)
12. When they are all tight (about as tight as when you loosened them, you are done).

When finished, you will probably agree that this job was really no worse than changing a diaper. (That's not sexist--I've changed my share. )

Wow you must be a professional instruction writer, very impressive.
I too save my old tooth brushes for jobs likes this but I am sure my children would say they were very happy that I did not use a toothbrush on their groves when changing their diapers.
I think diaper changing is easier
You should consider authoring a comprehensive book on practical RV maintenance and repair.
Thanks for posting your response.

[Larry-NC]

Originally Posted by johnandval

Wow you must be a professional instruction writer, very impressive.
I too save my old tooth brushes for jobs likes this but I am sure my children would say they were very happy that I did not use a toothbrush on their groves when changing their diapers.
I think diaper changing is easier
You should consider authoring a comprehensive book on practical RV maintenance and repair.
Thanks for posting your response.

Thank you. That's very kind of you.

Some may find it harder to work on wiggly, malleable objects (like babies) than stationary, solid objects.

I have written a few manuals and guides in the past. I seem to have a reputation for being detailed or long-winded, not sure which.