hi, i have johnathan wilson trad. while trying to fit connector to fuel sedimentor/filter for webasto supply i was unable to stop flow of diesel. on closer inspection of pipes fuel cut off is connected in fuel return line, ie pipe not going to 1st filter. engine as run ok even when low on diesel, does this mean pick up pipe & return pipe both go to bottom of tank or is fuel shut off just on wrong pipe? any thoughts greatly appreciated as i'm not sure if i should assume wrong pipe is connected or cut off is on wrong pipe, any ideas .