I have a 04 diesel 75. For quite some time, upon reaching half full, the needle on the fuel gauge would being to visibly rise and fall while driving or stationary. Members will know that the fuel tank contains two units - the 'sender' & the one with the pump. Had the 'sender' unit replaced about a month ago. To 'try it out', once I'd run the diesel down, I filled the tank to the brim. Upon reaching the half way point, while driving on fairly level ground, the same happened. Does anyone reckon I need to replace the unit with the pump please?