[medcrest]

Has anyone ever had work done on their fuel tank sending unit? I just bought this rig and the tank was full when I bought it (thanks, Jerry). At that time the gauge registered about 7/8's. Drove it about 350 miles home and it read 1/4. Running the engine the other day, the needle was barely off empty. No big puddles of diesel under the coach, so I'm assuming the sending unit is faulty. Does it use a float or some other form of measurement? And, as an aside, there is a small black knob in the upper left corner of the tank. Can anyone tell me what it is before I find out that it's the tank dump valve? I don't have a picture yet, but I can get one.