slow overflow in Koler toilet.

I have a five year old Koler toilet. Have a problem as follows:
After I flush it, the water tank fills up properly. However, after a few minutes it start to slowly overflow into the overflow column. I replaced the flapper; hence no leakage there. The float mechanism looks OK in that it stops water at the appropriate level; however, it continually and slowly overflows.
How do I fix this?
Any comments are greatly appreciated.
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Frank wrote:

The float/ballcock is not closing tightly. Repair/replace it.
Jim
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Jim:
Thanks a ton for helpful comments. Will do as you suggested. If you have time to write, what is best way to repair?
Thanks once again for your assistance,

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Frank wrote:

Buy a Fluidmaster, I got one for peanuts at Home Depot a couple of weeks ago. A no brainer to put in. Here's one now:
http://tinyurl.com/6htmq
Jeff

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Jeff Wisnia (W1BSV + Brass Rat '57 EE)

"As long as there are final exams, there will be prayer in public
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That "tinyurl" didn't do what I thought it would. Just look under "F" on the page which comes up, find "Fluidmaster" and find their model 400A fill valve.
Jeff
--
Jeff Wisnia (W1BSV + Brass Rat '57 EE)

"As long as there are final exams, there will be prayer in public
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<< what is best way to repair? >>
1) Call Kohler customer service. They are tops IMO. 2) Request a parts list for your toilet. 3) Order the needed parts (you may ask for help on this, they are pretty good at suggesting remedies) 4) Install parts. 5) Pat yourself on the back for reducing your water bill a bunch. 6) Keep this telephone number handy: 1800 456 4537 in case you need help later. 7) Call 1800 433 6287 for literature to inspire your next remodeling project, kitchen, bath, whatever.
HTH
Joe
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Thanks all for grest suggestions. I believe they will do the trick.
Thanks again for your support.

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