Our RV toilet bowl was not holding water anymore, so several years ago, I researched what to buy and how my husband should repair it. (I don’t do toilets.) I came across a now-long-lost YouTube video that showed you could get a little more time out of the rather nasty rubber seal with a coating of plumber’s grease. To the hardware store we went…
I put on a glove and smeared the plumber’s grease on the top and underneath the seal. It worked! Not only does it now hold water in the bowl, but the seal also helps prevent stinky sewer gases from the holding tank from seeping into the RV.
The seal dries out quickly when the RV is not used. A little bit of plumber’s grease helped soften the rubber seal and provided enough of a barrier to hold water. It has worked so well over multiple years that the tube is almost empty! Evidently, Vaseline will work too, but I never tried that.
One year, when we were storing the RV in the Arizona heat, I added water to the toilet and used cling wrap to cover the bowl to keep the water from evaporating and the seal from drying out. It is the same method we used on our AZ house when leaving for several months. It did work for a few months on the RV, but not as well as in an air-conditioned house.
Disclaimer: Is long-term use bad for the toilet or the holding tank? Frankly, I don’t know. Is it still holding water? Yep, and changing out the toilet seal is one less item on the never-ending list of things to fix on the RV!
You can find a variety of plumber’s grease here, or buy the one that Nanci used from Ace Hardware.
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RVT1269
Thanks for the tip, Nancy, the toilet in my motorhome will be getting this treatment today, thanks to you.
I just looked up the Plumbers grease from Ace. It states not to be used on rubber o rings or synthetics. Isn’t the toilet seal rubber?
Silicone grease is the correct thing to use on the ball seal. It is sold as plumbers grease and as dielectric grease. Vaseline is a petroleum product and really shouldn’t be used. However, before using silicone grease you should remove and clean the seal, Dawn Powerwash works great. Lube the underside of the seal and reinstall. Any lube on the top of the seal facing you isn’t of value.
also known as O-ring grease, this product is used in most ‘washerless’ sink faucets. It does not harm the rubber and it is food safe.
Another use for this grease (I keep a separate tube) is to grease the rubber seal inside your sewer slinky parts. (gloves recommended). Wipe out any gunk or grit with a paper towel, smear a little on the rubber. It both helps with leaks and I’ve never needed a wrench to separate parts when breaking down camp.