12j fuel system? help

[rolyrat]

Does anyone know where to put the one way valve on the diesel filter of a 12j engine? Does it go in the lift pump - filter line, or the injector pump leak off - fuel filter line? I think the latter, so the lift pump cant force diesel into the wrong end of the injector pump, if that makes sense. bit of an obsure question, i know. Any advice much appreciated.
Roland.