I think my truck is losing prime over night. The last couple of days it won't start unless I pump up the filter and bleed the system. I replaced the filter and rubber hoses from the filter to the hard lines and still losing prime. Anything else I could do to stop this from happening? Ken

 

It could be in the hard line section or anywhere along the frame to the tank.

It could also be the check valves in your lift pump or it could be your overflow valve.

do you notice it more with low fuel?

 

I just bought the truck last week. I've only used about a 1/4 tank so far. Wheres the overflow valve? I bought enough line to go back to the tank but after looking at the hard lines, they looked brand new so I decided just to replace the rubber ones.

 

You must be down south if they look good...

Um, the overflow valve is on the right front of the injection pump (sitting in the drivers seat).

It is also the fastner for the return line banjo.

 

I messed with fuel shutdown silonoid and it fired right up. I guess I need a new one or rebulid it. It looks like i'm gonna become a diesel mechanic (with everyone's help) before you know, and don't want to be

 

Take a look at the fuel heater. It's a hockey puck shaped thing down below the fuel filter. There are two little metal pins in it that get hot and melt the plastic surrounding the pins. This causes an air leak in the suction side of the fuel system. Just remove the fuel heater. I took mine out a couple years ago and have never had a problem starting the truck even in 10* weather.

 

check the relay on that solenoid. it's above the master cylinder.

 

My 95 did that and I found a leak at the return line at the back of the head-drivers side. It will leak air in when it sits over night. Mine got bad enough to finally leak a little fuel. I just slid the hose on it a little farther.

 

I think that we can rule that out now since I replaced the lines last night.