Slow leak in toilet tank

[garmp]

Our toilet had a slow leak from the tank into the bowl. About every 20 minutes you'd hear the tank refill. Terribly disturbing noise when you're trying to sleep! I put in a replacement kit and all was fine for a couple of weeks. Then it started again. About to drive me crazy. So I bought a complete Kohler replacement kit, including the gasket between tank and bowl, all for that specific model. Replaced every thing but the porcelain. Again all was fine for a couple of weeks. Then the tank began refilling again. This really gave me the jaws, so I bought a new toilet and had a contractor install it. Ahhh, peace and quiet again. Well that lasted about two months and now, the same friggin' thing. I'm at a loss. I just pulled the tank and made sure the flush valve was tight and there was no deposits on the flapper or seat. In about 20 minutes the tank refilled again. I put red food coloring in the tank and in a few minutes noticed the coloring in the bowl. So I know I got a leak some where.
Just took most of the water to right below where the flap seats on the valve trying to determine if the flapper wasn't seating or the valve seal was bad and haven't notices any more coloring.

I'm at a loss! can't keep replacing guts every other week. Any thoughts?
Please help!!!

 

[Zanne]

garmp, do you use any chemicals or cleaners in the toilet tank?
Also, do you have "hard water"?

Sometimes sediment from the water can build up in the fill valve mechanism and you have to take it apart and clean it.

This may sound like a strange idea, but have you considered turning the shutoff to the toilet water supply to reduce the amount of water going in to see if maybe it just needs a little lower water pressure?

I'm not a plumber or an expert, but I've had the toilet filling problem before. In my case it was caused by sediment.

 

[garmp]

No sediments not hard water. No grit nor grime. After a flush it takes about an hour for it to seep enough to refill and that only last a very short time. Then it's about every 20 minutes or so and very brief. Also the other bathroom, which back up to this one has had the same toilet for over 4 years and never a part replaced.

 

[Zanne]

No sediments not hard water. No grit nor grime. After a flush it takes about an hour for it to seep enough to refill and that only last a very short time. Then it's about every 20 minutes or so and very brief. Also the other bathroom, which back up to this one has had the same toilet for over 4 years and never a part replaced.

Hmm.. That is very strange. I have no idea!

I hope you can figure it out and/or that someone here can help you.

 

[havasu]

I'm guessing the chain is too tight, or the flapper seal is messed up. I'd recommend placing a weight on the flapper and letting it sit overnight to see if this is where the water is escaping from.