Cable Maintenance for Dump valves

dpgllg wrote:
I have 3 dump valves operated by cables. I've tried searching for how to maintain and lubricate them but haven't found much information.

What should I be doing to maintain them and what products should I be using? The pull handles are accessed through the front drivers side compartment below my Nautilus P1 water controls.

Thanks!

Dave

Years ago, trailer dump valves used to be mounted "externally" somewhere on the drain pipe/s - no cables. Easy access, easy to replace.
A cable means it's under the RV - not a fun job to replace!

However, *usually* the cable is the problem - not the valve.

The mfgrs do a poor (lousy!) job of routing the cables!
After years of use - pushing & pulling the handle/s, the cable (inside the sheath) may develop "slack" and/or a kink. Lube won't fix that.

Follow the cable from the handle to the valve. Look for excessive bends, etc. Is it binding? Have someone operate the pull handle for you. Watch the valve open and close - and how the cable "reacts".

The valve *may* be bad - solution = replace it, but it can be a real "PITA" (been there done that).

Skip the lube efforts! Try replacing *just* the cable before doing the valve - it's *not* expensive! Check Valterra (on Amazon) for parts.
If that solves the problem, you have saved yourself a LOT of grief!

BTW - (on edit) - Valterra makes an "twist-on" valve to attach to the end of the 3" drain. About $15. Handy temp fix when the "main" valve fails (hopefully in the open position).

Good luck!

.

How to lubricate a cable.. I won't tell you how to do it. Just how to learn.

Visit your local Harley Davidson (or other Brand) motorcycle Shop. They can show you and may even be able to sell you the tool needed. That easy. and trust me it is easy. but I want you to see it live.

schlep1967 wrote:

CarnationSailor wrote:
To dougrainer,

Thanks for the additional info. It has not gotten any worse since I bought the trailer 5 years ago, and it is not bad enough for me to tear into the coroplast liner. I'll wait for it to get worse - if it ever does.

If it does start getting worse, replace it before it breaks. It's much easier to rinse out a tank to the point of actually wanting to open up the plumbing when the valve is working.
If it gets too tight you can pull the cable/rod out of the gate valve and then you have to deal with a full or partially full tank when you remove the bolts.

"then you have to deal with a full or partially full tank"

Or just have someone else do it! :D

CarnationSailor wrote:
To dougrainer,

Thanks for the additional info. It has not gotten any worse since I bought the trailer 5 years ago, and it is not bad enough for me to tear into the coroplast liner. I'll wait for it to get worse - if it ever does.

If it does start getting worse, replace it before it breaks. It's much easier to rinse out a tank to the point of actually wanting to open up the plumbing when the valve is working.
If it gets too tight you can pull the cable/rod out of the gate valve and then you have to deal with a full or partially full tank when you remove the bolts.

To dougrainer,

Thanks for the additional info. It has not gotten any worse since I bought the trailer 5 years ago, and it is not bad enough for me to tear into the coroplast liner. I'll wait for it to get worse - if it ever does.

dougrainer wrote:

schlep1967 wrote:
I've never installed a new dump valve and I have never seen instructions for installing them. I have had to take mine apart. Most recently this week for repairs from a tire blow out that broke off the end of the drain. One thing I noticed is if you over tighten the four bolts that hold the valve together, it will be hard to open and close. If somebody did some work on yours the bolts may be too tight.
If nobody worked on it you might be due to replace the valve. Really not that hard to do depending on the location under the trailer and the creativeness the factory used.

You have never worked on a Cable driven Dump Valve system. "hard" to do? Not if you have NEVER worked on one:B It can be very frustrating. Doug

Read it again. I've never installed a new one. But I would guess the instructions that come with one would indicate how tight the bolts should be. I have removed and reinstalled two of them for other issues. And if you over-tighten the four bolts, you will have problems opening and closing the valve.

schlep1967 wrote:
I've never installed a new dump valve and I have never seen instructions for installing them. I have had to take mine apart. Most recently this week for repairs from a tire blow out that broke off the end of the drain. One thing I noticed is if you over tighten the four bolts that hold the valve together, it will be hard to open and close. If somebody did some work on yours the bolts may be too tight.
If nobody worked on it you might be due to replace the valve. Really not that hard to do depending on the location under the trailer and the creativeness the factory used.

You have never worked on a Cable driven Dump Valve system. "hard" to do? Not if you have NEVER worked on one:B It can be very frustrating. Doug

CarnationSailor wrote:

dougrainer wrote:
There really is no maintenance. It all depends on how the OEM looped the cables when installing. I have one of these from years ago and used it on the old Motorhome Heater control cables. I guess to could use it on the Valve cables. This tool allows you to inject WD 40 or similiar thru the interior of the cable where it slides. Doug

The description of the product you provided a link to does not say how it is used. If access to the entire length of the cable is required, then it won't work for me where I have zero ready access to the cable. I've squirted WD-40 where the cable enters the outer sheath, but that doesn't help. Also, only one of three cables is hard to operate and it has been this way since new 5 years ago, so maybe it is not a lubrication issue.

What you have to do is, access the actual Valve. Remove the Cable from the valve and then install this tool and spray the lube. What the tool does is clamp OVER the outer sheath and the tool then seals when you tighten it. YOu then insert the plastic spray tube from the WD 40 into the rubber grommet hole of that tool and spray until it comes out the other end of the cable. You cannot do this from the Handle end of the Valve system. Doug

dougrainer wrote:
There really is no maintenance. It all depends on how the OEM looped the cables when installing. I have one of these from years ago and used it on the old Motorhome Heater control cables. I guess to could use it on the Valve cables. This tool allows you to inject WD 40 or similiar thru the interior of the cable where it slides. Doug

The description of the product you provided a link to does not say how it is used. If access to the entire length of the cable is required, then it won't work for me where I have zero ready access to the cable. I've squirted WD-40 where the cable enters the outer sheath, but that doesn't help. Also, only one of three cables is hard to operate and it has been this way since new 5 years ago, so maybe it is not a lubrication issue.

I've never installed a new dump valve and I have never seen instructions for installing them. I have had to take mine apart. Most recently this week for repairs from a tire blow out that broke off the end of the drain. One thing I noticed is if you over tighten the four bolts that hold the valve together, it will be hard to open and close. If somebody did some work on yours the bolts may be too tight.
If nobody worked on it you might be due to replace the valve. Really not that hard to do depending on the location under the trailer and the creativeness the factory used.