good lubricant for shut off valves?

[vocalmama]

Hey there! It would appear we have a small leak at our valve cut off. While running some tests, we noticed that both the grey & black water valves are very hard to push and pull. We've heard using things like wd40 can make the mechanism swell. Is this true? And if so, can someone suggest a lubricant we can safely use? We have a 1989 skyline Layton we bought 2 months ago and just started using. I am loving it! Thanks!

[Wanabee FTer]

I use Shinitsu grease on all my rubber seals. It's expensive, but I have never found anything better. You should be able to use a silicone based spray lube like "rubber seal conditioner" available at Walmart's RV section.

You are correct, WD40 should never be used on rubber seals, it is a solvent not a seal conditioner.

[FRR2EYW]

If the seals are difficult to move or in doubt, I would suggest replacing them while they still work. This is something that can be very unpleasant in the event of a failure. Two new gates, knife valves, or whatever you want to call them are a small price to pay to avoid a black water shower. Trust me. Experience is a great teacher, the lessons are not usually forgotten.

[teddyu]

Go to HD and get some plumbers silicone grease. The container is about the size of a silver dollar and not to costly. And like Brylcreme, just a little dab will do ya, with the vavle openned, apply to the shaft, exercise the valve, then relub. Should fix the problem. Just my two cents...

[Mr_D]

At least one of the toilet chemicals (TST) contains coconut oil. I've never had a valve seal need replacing in the time I've been RV'ing (since 1957).

[Shadowcatche]

Never ever use anything that has any petroleum products to lubricate rubber, it will cause it to deteriorate. Silicone grease as recommended and a little known, chlorine. Chlorination of rubber makes is slippery.

[mikf]

Originally Posted by Wanabee FTer

I use Shinitsu grease on all my rubber seals. It's expensive, but I have never found anything better. You should be able to use a silicone based spray lube like "rubber seal conditioner" available at Walmart's RV section

.

how do you get the grease on the seals of the holding tanks. or are you talking about something else?

[Wanabee FTer]

Originally Posted by mikf

.

how do you get the grease on the seals of the holding tanks. or are you talking about something else?

I use silicone grease to lube any rubber seals.
To tell you the truth, I have never tried to lube gate valves. Mine were sticky so I replaced them. New ones are cheap compared to the hassle of trying to lube the valve, and they are so easy to replace.

I have heard of people drilling a small hole at the top of the gate to be able to stick a silicone spray lube straw into it.

[Dutch Star Don]

For about $30.00, you can buy two new valves. If yours are in an accessible area, you can replace them in about 20 minutes if you're handy. Its not worth trying to lube them if they're leaking or stiff.

[EngineerMike]

SuperLube is a good silicone based grease for rubber seals in water based plumbing. Its NSF approved so you can use it on potable water valves, etc., tho that's not a concern for the OP.

However, the valves likely have 4 bolts holding a flange & now hardened seals together, and subject to some calm jimmying on the adjacent plumbing pipes, are easily replaced by most DIY'ers. Obviously, empty the tanks & flush first. I did this on my Trek years ago, and valves went from way hard to deal with, twisting & wiggling & herfing so hard I thought I'd break something; after the fix the new valves slide sweet & easy. Great fixit.

[Larry & Rita]

Over the years I've heard a number of "Great Ideas" from drilling a hole and installing a grease zert to a cup of vegetable oil in the tank prior to dumping.
Shade tree mech. are great people and what might seem to work for one won't work for another.
I have found the best "ounce of prevention" is to repalce the broken part and be happy.
New works over and over-repaired just prolongs the headache.
jmho
Larry

[Tha_Rooster]

If you have to break your valves down to grease with silicone, grease or anything else why not replace it while your there. I would try coconut oil and work the valve several times if it works great if not replace. There is nothing worst than a leaky black valve.

[Grumpy Dave]

try Fluid Film® | Corrosion Preventative, Lubricant and Rust Inhibitor . Lanolin based rust preventative and lubricant. I use it on everything , can't see why it wouldn't work for this as well. I have no monetary investment other than what I spend buying it.