Repairing the RV Toilet Seal

It is recommended that the RV toilet bowl always contain some water. This practice assists in two areas. First it allows for easy disposal of solid contents including paper and it forms a water seal to block out black tank odors. There are times however, when the seal fails to operate correctly. When this occurs, retention of water in the bowl is not successful.

Our forum members have submitted tips for solving this particular problem:

Tom and Barb advise:

Try turning off the water and draining running all the water out of the toilet. Spray silicone onto the valve until the valve is covered and let it sit for a few hours. If the silicone drains out repeat. The silicon should swell the seal and it should hold water afterwards. This has worked for me several times and was recommended by Thetford. They also sell a product that will do the same thing. Make sure the valve and seal are clean.

Alan and Trish advise:

As you flush the head, have another person pull the fuse so as to leave the hole wide open; use a bushy toilet brush and make sure there is no debris caught on the inner lip. Treat with silicon grease. Replace the fuse.

Try the brush while holding foot on the pedal :) I do find that the silicon grease is more tenacious that the spray lube. I would shy from petroleum grease as some advocate.

If you do use the grease, be certain not to touch your eyes...it is an extreme eye irritant. If you use a finger, at least triple wash your hands, and still do not touch your eyes.

John and Linda advise:

If you have the manual foot pedal flush in front of the toilet you may have the problem I had. The foot pedal would rub against the cover behind it and would not close all the way. I would let pedal pop up hard and it would hold water. Had that fixed later and it works good now. You could also be having a problem with the seal.

Hollis advises:

Over the years I've used both the spray silicone and the silicone grease (Home Depot in plumbing aisle, but such a small can that it is difficult to find sometimes.), but have found the grease to be longer lasting and more effective. Just put on some rubber gloves and smear it all around the center ball and outer seals. Our Phaeton leaked so much that it would only hold water for a few minutes. Put on some silicone in September, and "bingo" the leak was cured. In fact, I stored the coach around October 7th and today, when we went to pick it up, it still had water in the toilet. The grease will, in our experience last for several months.

Dynamo 1118 advises:

Try wearing rubber gloves to prevent getting the grease on hands, eyes, and to be more sanitary.

Submitted by Mike Sundberg - 12/09/07