There was a factory thing on that toilet and they were furnishing replacement parts for free . Dont know if they still do that.
There is quite a blowup (illustration) on escapees.com about those things, and it tells how to meausre the pressure required on the holding strap that controls the pressure on the seals. Might go read that part and see if it helps you.
KMC6970 wrote: We found out that a quick lift on the pedal after flushing will seal the water in. Only took me ten years to figure it out.
That is what I found out but it only took me a year. I cleaned the seals and sprayed it with silicone. Each time the fix only lasted a week. A quick lift on the pedal with your foot is all it takes.
We too took almost a year to realize the pedal has to "snap" back to seal properly. We also got the replacement, re-designed, seal kit from Dometic for no charge...they said, "should've called us sooner, we'd have replaced it right away"....DUH!! Had I known about the problems, and subsequent re-design, I would have contacted them earlier!!!
I just checked mine and found the seal slightly off center. Loosened the band clamp, recentered the bowl over the seal and tightened the clamp. Will let it sit there til tomorrow. Will know by then if that did the trick. If not, lifting the pedal will continue as standard practice. I guess I can always get the redesigned seal if I grow tired of that.