My Groco model K toilet (with electric drive) is leaking around the
shaft seal. I've rebuilt the darn thing twice in two years, taking 6
hours and about $100 for the kit. Why does it leak?

When I winterize it I pumped pink antifreeze (propylene glycol, I
think) through the head, the lines, and into the holding tank, then
pumped out the holding tank. Any idea if this created the problem?

Any other causes?

Bob Hargraves