I would like to install on a one piece Kohler toilet a bidet. When I tried to unscrew the screw from the seat, it just didn't move, not with the screwdriver nor the drill. So I put wd40 but still doesn't move. Can u please help me.
We have 3 Kohler 1-piece Rialto toilets. I replaced the seats on all 3 of them. The first two took about 2 minutes each. Unscrew bolt, replace seat, re-screw bolt. But the 3rd toilet had bolts that would not budge. I bought an impact screwdriver from Amazon and went to work. Using a small sledge hammer the first bolt finally loosened after about 30 blows. What a workout! The second bolt was more stubborn and the groove (flathead) at the top was beginning to widen causing the flathead bit to slip. I used layers of heavy gauze and plastic waterproof tape to narrow the groove and finally got the thing to unscrew. What a pain!
This problem is caused by a basic design error. The bolt is stainless steel and the anchor is aluminum. These metals are never supposed to be used together in a fastener due to galvanic / bimetallic corrosion. This is particularly true on a toilet seat where the anchor will be exposed to acidic / alkaline fluids and cleaning products, which promote galvanic corrosion. The aluminum anchor will corrode and 'glue' itself to the bolt.
I just ordered a replacement set, hoping that they fixed this Engineering 101 problem. Nope! Same aluminum post with a stainless steel bolt. See the photos below.
I notified Kohler and sent them a galvanic corrosion metals chart and photos. No reply yet. I did find one potential online source for stainless steel molly / sleeve expansion bolts.