c_shah wrote:
I replace my 20 years old toilet (KOHLER) with a new fill value (made
by MJSI www.gomjsi.com) and a flapper. It still leaks..at about 4
hours tank is empty looks like it is leaking into bowl (no water
around toilet area)

At this point I am not sure what could be causing it to leak? should I
try another flapper...
I know many people will say this is NG,
but I have done it for many, many
years without a problem. I put a thin
layer of petroleum jelly on the rubber.
I know, petroleum and rubber don't get
along, however, as I said, the
rubber never deteriorated from this.
BTW, I think one of the problems
with leakage is due to the lower flush
toilet having less "head pressure" due
to shorter tanks. With the older
toilets, higher tanks meant more pressure
on the flap, leading to a tighter seal.