Leaking Tank Hold Down Bolts

I have an American Standard toilet that was installed approximately 15 years ago. A couple of days ago I noticed some dampness on the floor around the toilet...especially toward the back. I found that both tank hold down bolts were dripping. One of the nuts was so loose I could turn it by hand. Up until a couple of days ago never any problem. Any ideas on why this happens? Do the washer under the screw heads inside the tank get worn and compressed over time? Could the gasket between the tank and bowl weaken and compress over time? I snugged the hold down bolts and the leaking has stopped. The exact same thing happened to my neighbor. He has a Kohler toilet. I suggested he snug the hold down bolts and his toilet leak stopped.
I am going to get a new hold down kit and tank bowl gasket and replace them.
I don't want to overthink this but am just curious as to what others might have discovered.

some tanks will sit right on the bowl when put together.
Some won't snug down 100% and over time the gasket does get soft and id the bowl is bumped the whole thing goes to crap.
Kohlers often have a 3 bolt gaskets with plug tha goes trough the hole with the bolt.

If there is room between the tank and bowl snug a metal washer and nut on bottom of tank before you set the tank. can't always do that because of to close of tolerance between the tank and bowl.

DO NOT put a metal washer between the head of the bolt and the neoprene washer before you put it through the hole in the tank.
It defeats the purpose of the neoprene sealing against the head and the tank.
Just use a the neoprene washer under the head. Then a washer and a nut on the bottom side of tank, if there is room.

Mr_David said:

some tanks will sit right on the bowl when put together.
Some won't snug down 100% and over time the gasket does get soft and id the bowl is bumped the whole thing goes to crap.
Kohlers often have a 3 bolt gaskets with plug tha goes trough the hole with the bolt.

If there is room between the tank and bowl snug a metal washer and nut on bottom of tank before you set the tank. can't always do that because of to close of tolerance between the tank and bowl.

DO NOT put a metal washer between the head of the bolt and the neoprene washer before you put it through the hole in the tank.
It defeats the purpose of the neoprene sealing against the head and the tank.
Just use a the neoprene washer under the head. Then a washer and a nut on the bottom side of tank, if there is room.

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Thank You.
The Kohler replacement kit looks really good. It is one piece that incorporates the tank to bowl gasket and 3 rubber bolt gaskets that extend through the bolt holes and the bolt heads and shafts are rubber coated for about an inch. The Kohler is for my neighbor....haven't replaced it yet as tightening the original bolts have stopped the water leaks.
The American Standard is in my house and I'm waiting for the kit to be delivered.....but not leaking since I tightened the bolts a few days ago.
Would you advise installing the new parts now or just waiting until if/when the leaks start up again?

I won't leak again until after you leave on that 1 week vacation.

I like the new coated bolts in that kit. The old style bolts try to push out the rubber stems that goes through the tank holes when you tight them down.

Mr_David said:

I won't leak again until after you leave on that 1 week vacation.

Click to expand...

Haven't been on vacation in 6 years and there won't be one as long as my wife's mother is still on earth...and seeing as how only the good die young I don't see us going on vacation anytime soon.
Based on that logic I guess no need to install the new kit.

Mr_David said:

I like the new coated bolts in that kit. The old style bolts try to push out the rubber stems that goes through the tank holes when you tight them down.

Click to expand...

Yes, the Kohler bolt kit with those bolts seems really nice. I hope the American Standard bolt kit has a similar design.

The American Standard kit arrived today. Just bolts, washers, and nuts. They should have taken a hint from Kohler's design.

I was at HD awhile back looking for some extra BRASS tank bolts.
All they have was brass coated steel bolts. Check yours with a magnet. I would not be surprised if they were steel bolts as well.