There is an axtra rubber tube coming from the top of my sender unit.Haynes manual photo does not show it .Can any one tell me were it should connect to. there is fuel feed,fuel return.feed for fuel burning heater, and electrical connection for sender unit. and one small bore tube that is not shown in haynes photo or text. THERE IS A photo of this in haynes manual page 4B-3 FREELANDER TD4 54 REG. DONT NO HOW TO POST MY PHOTOS TO SHOW THE DIFFERANCE.