Black tank valve really hard to close

[Dennis66]

My 2021 303rls the black tank valve keeps getting harder to close, how hard is it to get to the valve? I have it at the dealer and last time they said that is normal, Im afraid Ill be out camping and it wont work at all.

[Yoda]

My 2021 303rls the black tank valve keeps getting harder to close, how hard is it to get to the valve? I have it at the dealer and last time they said that is normal, Im afraid Ill be out camping and it wont work at all.

While I have not done this yet I am planning to try it. This tip came from a post over at another RV site. It uses a 1/2" clear hose. You remover the handle and thread a roughly 3' piece on the the threads over the inner cable of the bulkhead fitting (hose will stretch over threads to give a tight seal) . Then fill with several inches of lubricant (I plan to us silicone spray ) then add slight air pressure (air hose / caned air) and force the fluid into the inside of the cable jacket. You do this while holding the hose up. The tip said it would take several minutes for the fluid to penetrate up and around any cable loops. This should lubricate the cable, but will not get to the the valve body itself.

When I try this next week when it warms up again, I will document what I do.

But if your rig is at the dealer ask them to check again.

[Cate&Rob]

This topic has been discussed at length in several threads. If you use the search tool in the upper right corner on "gate valve" and my user name, you will find most of these threads.

To summarize . . .
1) Two ways to get at a gate valve are lower the coroplast or cut an opening in it. A cut opening will not likely give you enough access to solve the problem.
2) Most likely that the gate valve itself is sticking. Lubricating the cable will not reach the gate valve.
3) Cable routing and alignment with the gate valve are important. (The factory does not do a good job of this . . . see Valterra instructions in the referenced threads)
4) My solution of adding a zerk grease fitting to the gate valve continues to work well for me and has worked well for others.

Rob

[JBill9694]

There could be several reasons for the black tank valve being hard to close. Let's start with the less destructive to investigate and move on from there.

The maybe something hung up on the valve opening that is preventing the gate from closing easily. With the valve open pour a bucket of water down the toilet and see if this makes the valve easier to operate. Repeat as necessary until operation improves or satisfied that this is not the problem.

A variation on the above would be to use a reverse flush adaptor. Same principle, just allows for more water to be used for the flushing.

Look at the exposed stem of the cable pull if there is discoloration, staining, or rust on the stem then moisture or grit is in what I'll term the scabbard section of the cable sheath that contains the stem when the valve is closed. There are many posts here on how to get get oil or grease into the scabbard but IMHO it is time to replace the cable. Whether the cable needs to be replaced or not, the next step is to access the cable routing and the drain valve. This will entail removing the basement back wall and dropping the belly cover to access the cable routing and the drain valve. There are many posts addressing the how to do this. Basically it's a matter of removing screws.

Check the routing of the cable. Most likely it was not installed per the manufacturer's instructions with 6" straight sections at the ends, clamps at 2' spacing and 2' diameter bends. Try to improve the routing and see if this improves operation of the valve. If not it is time to disconnect the cable from from the drain valve and check it's operation.

In post 5 of Grey tank handle - Grand Design Owners Forums (gdrvowners.com) I go into detail on how to disconnect and reconnect the cable. There are other posts and YouTube videos on this too. With cable disconnected the operation of the valve can be checked with a long stem screwdriver or other object, just make sure that you have some way to pull the valve open again.

I haven't had to replace a valve or try to improve a valve operation. Others have and will be along to provide suggestions for that operation.

[ThePowells]

I'll address your basic question. The difficulty factor depends entirely on the ability to access the valve. The valve consists of four bolts and is an easy replacement or cleaning. You may want to try a vegtable or Olive oil in an empty tank to try and lubricate the valve.

[DarnDave]

Having already lived thru this dream on my last trailer, I took a preemptive strike with this one. I had the dealer change the black valve out for one that had a threaded shaft (necessary) and installed an electric actuator valve made by Baxter. Swapped out the fuse for a resettable circuit breaker. Under $200 for parts and an hour labor and no more drama. This and "good neighbor" twist on valves at my exit tubes, and I feel I am good to go. About 90 camp nights this year and all is well.

[Dennis66]

Well the dealer pulled down the bottom found the cable was to short causing it to bind. He said it was a 6' and they installed a 8'. I have not tried it out yet I will be picking it up on Monday fingers crossed

[ThePowells]

As Dennis66 posted, a too short cable can create a hard to pull / push problem with the valves. The difference between my black / gray tanks is day and night. I pointed out the bend in my back and forth with CS when my black tank valve failed..

[Trrbossman1]

I had the same problem with my black tank valve. After different lubricating methods and attempts it still wasn’t operating correctly. (Wouldn’t close completely) Finally I removed the lower cover of the camper to access the valve. Removed it cleaned it and checked the two rubber seals. It’s when reassembling the valve I noticed the outside sheathing of the cable was not the correct length. It was keeping the cable itself from fully extending. After trimming approximately one inch of the outside covering everything worked as it should.