Toilet base leak

Check to make sure it's not from the water source or the pedal. Don't tighten down to tight it's a rubber seal not a wax like house.

Toilet floor flange bolts (just like residential toilet) should be SNUG

Tighten them too much and you will:
Crack toilet base
Warp toilet base
Cause floor flange to leak

Floor flange 'gasket' is more of an 'odor' seal than a 'moisture' seal
Yes it stops water from leaking out but majority of water when flushing drops straight down into drain line from toilet to waste tank


If you are finding 'water' on floor around toilet...

Lay several sheets of TP around toilet base
Some under water supply assembly
Some directly under 'vacuum breaker'

Most of the time ---------vacuum breaker is cause of intermittent leaks
Small hole in top of vacuum breaker doesn't always get sealed when water supply assembly OPENS and will spurt some out

My leak was just as Ole Biscuit described.

Had to put a new vacuum breaker on it.

99 percent of the time it is not the base seal. Do as others have suggested and keep looking at the water valve or vacuum breaker.

Get a new Donut Seal, remove toilet and inspect all carefully. If a leak starts to rot the floor, it's the beginning of sorrows. You may be able to correct a problem now and prevent big trouble later.

AND.....make sure you aren't leaving too much water in the bowl while going down the road.

I was just about to start tearing things apart looking for a leak when I realized that it only showed up after being moved.

Leaving only a couple of ounces in there to cover the seal solved the problem.

I had this problem and replaced the seal twice and then did some closer inspection and found that the base that holds the retaining bolts was cracked. Went to Lowe's and got a new one. Cut the old one out with my Dremel tool. Glued the new one in. Problem fixed.
Not a fun job but necessary.
Busyguy

I meant to say the flange in the floor was cracked and had nothing to do with the toilet itself. Sorry if I got you confused.
Busyguy

When I repaired ours, there were threaded flanges in both male and female, as well as apparently the glued versions busy mentions. I got the threaded one the RV parts shop said was the most popular, took it home and it fit.

Potential problem is, if the floor rots out, weight of toilet with occupant crushes down onto the black tank and can crack it.

Thetford sells a "pedestal" that's a spacer base with a much larger footprint than most toilets. It can help spread weight out across the floor.