Can Anyone help?????

Do you pre fill the filters before installing them? I do on mine & never had a issue, but have a older C12.

 

I had this problem once, check all your connections and fuel lines. I saw peterbilt mechanic put a clear nipple in line to detect air bubbles. this was after several times in the shop. Replaced fuel lines, problem solved.

 

change pressure relief valve.screws into primary filter housing (1 inch fitting)about $40 CAT part.

 

Also check draw lines at tank, have known these fittings to lossen up and cause problems.

 

Another problem that i've had. also, not sure which primary filter housing/filter you are using, but double check that if it uses an oring in the threaded housing, it is there, and vica versa, if it isn't supposed to use one, there isn't one there.