Dump Valve Lubricant

[bluka43]

I've recently replaced the slide valve seals on the black water tank. check for leaks and none seen. The valve seems to be a little harder to operate when no liquid is in the tank. I don't believe the bolts are too tight, because it worked fairly freely when I first put it back together. I'm thinking that I need to use a valve seal lubricant at this point. Any suggestions as to what to purchase to use?
Thanks

[RLS7201]

ernie1 wrote:
Can't say exactly what material the dump valve seals are but absolutely do not use any petroleum based lubricant on them. They WILL swell and cause all sorts of problems. Use a silicone based lubricant and not a petroleum based one!

I installed grease zerks in my dump valves over 10 years ago, and my seals haven't swelled yet. Again, petroleum will not hurt the dump valve seals. They are not rubber. Most likely, they are buna-N.

Richard

[joelc]

ernie1 wrote:
Can't say exactly what material the dump valve seals are but absolutely do not use any petroleum based lubricant on them. They WILL swell and cause all sorts of problems. Use a silicone based lubricant and not a petroleum based one!

I would agree. There are many warning in multiple RV parts not to use anything that is petroleum based, so why take a chance when a silicone product will work. Not to change the subject, but on the slide seals they say to use silicone spray and on my Big Foot system they say silicone or Teflon spray. YOU DO NOT USE SILICONE CALK HOWEVER.

[ernie1]

Can't say exactly what material the dump valve seals are but absolutely do not use any petroleum based lubricant on them. They WILL swell and cause all sorts of problems. Use a silicone based lubricant and not a petroleum based one!

[RLS7201]

joshuajim wrote:
Plumbers grease comes in 2 varieties. Petroleum based and silicone based. Never use the petroleum based grease on any rubber seal as it causes the rubber to swell and will make the problem worse.

Unfortunately, most big box stores sell the petroleum based grease.

The dump valve seals are NOT rubber, so grease in not a problem.

Richard

[joshuajim]

Plumbers grease comes in 2 varieties. Petroleum based and silicone based. Never use the petroleum based grease on any rubber seal as it causes the rubber to swell and will make the problem worse.

Unfortunately, most big box stores sell the petroleum based grease.

[brulaz]

Because the newer trailer has enclosed, hard-to-get-at valves, have been pouring Thetford Drain valve lube down the drains a couple of times a year, after emptying the tanks in prep for storage, for the last couple of years. So far the valves are good.

Previous trailer I just used silicone spray as the valves were easy to get at.

[RLS7201]

Gjac wrote:
The easiest way to lube the dumpvalves is to install a grease fitting on the top. When ever the handle gets hard to pull usually every other year I pump some grease in and it pulls out and in with ease. For some reason the black tank always gets harder to pull than the grey.

Ditto.. Been doing the same for over 20 years. Never replaced the whole valve, just the $2.00 seals.

Richard

[Traveler_II]

I just use mineral oil, empty the tank and add about a cup once a month when we are on the road.

[Gjac]

The easiest way to lube the dumpvalves is to install a grease fitting on the top. When ever the handle gets hard to pull usually every other year I pump some grease in and it pulls out and in with ease. For some reason the black tank always gets harder to pull than the grey.

[larry_barnhart]

When our black water valve becomes hard to pull and push I drain the tank and pour a gallon of vegetable oil down the toilet and wait for as long as I can and then pull and push as fast as possible as the oil drains though the valve. Has worked for every time.

chevman

[joelc]

If it is just a lubricant you want you can get it anywhere. If you want a chemical that breaks down waste along with a lubricant, try Odorlos. I have used it for along time and love it. After I dump, I put some in the toilet and let it sit for awhile. It keeps my toilet seal and the valve well lubricated.

[RJsfishin]

2oldman is right !!
I will NEVER replace just the seals again I've done it twice, and just a waste of time and money.
For whatever reason a new complete valve works so easy......unbelievable.

[mockturtle]

I periodically clean and spray the extended valve stems with silicone lubricant. Seems to keep them working smoothly.

[2oldman]

bluka43 wrote:
I've recently replaced the slide valve seals on the black water tank.

You went to all that trouble and didn't replace the valve itself? A new valve would slide just fine.

[3oaks]

If the valve is located near the outlet where you can see it, spray the inside of the valve with silicone spay while working it open and closed.