92 Suburban fuel gauge/float stuck

[krammit]

My fuel gauge is stuck reading at 3/4 full(even when truck is off). If I fill the tank all the way full the gauge will move and read a full tank, until the fuel gets below 3/4 of a tank and the gauge stops there again. It's like the float will raise above the 3/4 mark but wont come down below it. I dont see it being a problem with the gauge but I can't be sure. I bought the truck recently with 240k, which is really good for a 20 year old truck. So I'm guessing it sat for a couple years and something corroded in place during that time. What can I do about this without dropping the tank and replacing the unit? Are there any cleaning additives that may help? I'm tired of trying to judge fuel by mileage alone all the time.

[txab]

You can try giving it a healthy does of Chevron Techron Concentrate Fuel System cleaner. Like a double dose. It works in some cases. Your sending unit may simply be worn out. It happens