Kohler & Flushmate 503 Flush Issue, Water Level

[briansmack]

Hello - I have a Kohler 3554 (floor mount, wall exit toilet - terrible but thats another discussion) with a Flushmate 503 pressure tank.
I installed 2 of these units at the same time, roughly ~10 years ago.

unit #1 is still working great and is consistent as always, the "flush/jet" time from the pressure tank and routine bowl water level.
unit #2 recently starting behaving oddly where the "flush/jet" time has essentially doubled, and the water level in the bowl is now lower, especially compared to the identical unit. Being 10 years old, I just replaced the cartridge, duckbill, etc but the problem still continues...I am stumped knowing that there are really no adjustments that can be made to the Flushmate...

When I state "flush/jet" time, I refer to time from pressing the lever to when the pressure tank starts emptying the water pressure in the bowl jet to when it cuts off and bowl starts refilling. Unit #1 is ~6-7 seconds...Unit #2 nearly doubled to ~12 seconds! I have to think this extensive time is contributing to the bowl level being lower as well.

Any thoughts please? What would be causing the pressure tank to be "emptying" for so much longer then the other...

 

[takedak]

Any resolution to the Flushmate 503/Kohler issue? The cartridge in my Flushmate was recently replaced and ever since then I've had the exact issue with the long flush time/low water level in the bowl.

I'm curious if there is a fix to this.