fuel gauge

The fuel gauge on my 99 z71 is acting weird.. I searched on here and nothing sounded like my problem but maybe this is normal..

If the fuel level is between 1/4 and 1/2 and i hit the breaks it will go all the way to E and the Low Fuel light will go on. Then when i hit the gas from a stop it will go up to about 3/4 of a tank. If im stoped or just cruzin it will read fine.. Whats the deal???

Thanks

Bad sending unit. Its in the tank.

yep....just wait till it starts jumpin all over the place. mine did that and now its at the point where when I fill it up it goes to empty and then when I start driving it goes to full and stays there.