after my truck sits a few hours it loses prime to the pump i just replaced the ip thinking maybe it was hard starting because of that it had 170 000 miles so i figured either way it would need to be replaced sooner or later. i was doing some searching and i read that i might be leaking air through my schrator valve if this is true can someone please let me know of the where abouts of it i heard a new tire cap with a rubber gasket could fix the problem so that maked me think it is that little cap on the driver side of my fuel filter assembly top side any help is greatly appreciated everyone here on oilburners has been a great help over the last year i have own my new to me diesel BTW it a 1994 7.3 with factory turbo thanks again