View Full Version : Leaky toilet gasket

05-12-2019, 07:03 AM
What can I use on the toilet bowl gasket to prevent water from draining out?

05-12-2019, 07:05 AM
Plumberís grease applied to the rubber seal.

05-12-2019, 07:41 AM
Plumberís grease applied to the rubber seal.
None of that grease available right now. Hozabout the spray stuff I use on the slide out boots? Or silicone spray? Vaseline petroleum jelly? Got those. Thank you.

05-12-2019, 09:24 AM
Did you get in there and clean the surfaces of the gasket and flush ball? Crud builds up on the surfaces from hard water and this is one of the leak starters.

05-12-2019, 09:31 AM
They make a better-than-wax toilet base seal now. I would think that this would be better suited to down-the-road RV's: https://www.homedepot.com/p/Fluidmaster-Better-than-Wax-Universal-Toilet-Seal-7530P24/205762183

05-12-2019, 10:39 AM
A tip on one of the RV repair sites suggested baby oil. Cover the seal with about an inch of the oil and let it sit. I usually put some in the bowl before I take the trailer to storage so it keeps the seal from drying out. This also, when flushed, helps lube the seals in the drain valves so they do not stick when you are draining the tank.

05-12-2019, 10:49 AM
Dometic says:

Please follow the procedures below before attempting to replace the seal.
1. Hold flush ball in full open position by pressing on pedal.
2. Using finger, apply moderate downward pressure around edge of ball seal.
3. Close flush ball.
4. Keeping flush ball closed, pour one quart of hot tap water into toilet bowl.
5. Let water cool completely.
6. Check for leak.

I'd suggest putting the hot tap water in the bowl first, let it set for 30 seconds, then apply moderate downward pressure working your way around the edge of the seal.

The toilet bowl should be at room temperature before adding hot water. Don't do this when the toilet is cold.

05-12-2019, 07:08 PM
I have been using liquid dishwashing soap for years. Just put a small amount around seal once in a while. You get a twofer for rhis a soap is very good at cleaing tank also.

05-12-2019, 07:15 PM
Before storage for a long period of time put RV antifreeze in it as well as in all the traps. It should not dry out.

05-12-2019, 09:06 PM
I read the original post again, an see that it is the BOWL seal not the BASE seal the poster is concerned with. A continuing problem.

1. A little GOOD dishwashing detergent (Dawn or Dawn equivilant) in the bowl occasionally helps.

2. There is an improved seal system out there that is advertised as "Stop the Leaking" on E-Bay: https://www.ebay.com/itm/New-JSP-STOP-THE-LEAKING-Fits-Dometic-385311462-improved-RV-toilet-seal-ring-kit/132934201918?hash=item1ef37ef23e:g:3ckAAOSwgIRcsJp 5

3. Thedford sells a toilet seal lubricant and conditioner. https://www.rvupgradestore.com/td-Toilet-Seal-Lubricant-Conditioner-p/83-1665.htm I seem to remember reading on an RV site somewhere that this stuff was just coconut oil. So I buy coconut oil at the dollar store, melt it (it doesn't become liquid until about 90 degrees), and pour it into the dry toilet bowl.

4. I like to spray a little TriFlow oil in with the pedal depressed to help lube the ball pivot points, for a better closing/sealing action of the ball valve.

BTW, if you are going to replace the seal, you might as well install a shutoff valve on the fresh water supply for cleaning and emergency water shutoff needs. This Sharkbite valve doesn't require any crimping - you just cut the toilet water line where you want to install the valve, and push the 2 ends of the tubing into the valve connectors. They don't seem to leak. https://www.homedepot.com/p/SharkBite-1-2-in-Push-to-Connect-Brass-Ball-Valve-22222-0000LF/202270642

05-12-2019, 09:24 PM
For this very reason I ditched my Thedford toilet and put in a Dometic. After two years no problem so far.