what cud is be cracked line??? if so how do i tell what line it is? im new to diesels dont much about them

 

If you are getting air in the filter it might help to know when it occurs?
At cold start after sitting?
If so look at the O rings for the fuel heater and the water in fuel sensor-they are in the filter housing,fuel heater is in the bottom and WIF sensor is in the side.
Another possible leak could be from the water in fuel drain but that should be a massive fuel leak in the engine valley.

If air gets in the filter housing while running you have a massive leak more than likely between the fuel level in the tank and the lift pump.

 

its been getting air in the lines for the last 3 weeks but i could bleed it out, and it would run good for like 30 mins or so. now when i try to bleed the lines its just straight bubbles, when i jump the fuel pump off of the relay it sounds weak, its used to sound strong before recently. could that be why its getting bubbles?

 

You very likely have a massive hole in the fuel line where it enters the tank-debris rests there and they rot the sending unit.

That will cause the air and the LP to sound bad.

A bad fuel cap could also be a contributing factor.

 

will it also cause it sputter after warming up?

 

Year of the truck can be more of a factor but anytime air gets in the fuel the engine will run poorly-surging and low power is common,stalling is also possible.

 

its a 95, and do i have to drop the tank, and if so , how? the metal lines coming out of the top of the tank are rusted

 

I would drop the tank or remove the box-the rusted lines are your problem.

With a 95 the air confuses the optic sensor in the IP and causes a lot of running problems.

 

how do i drop the tank

 

Remove the filler tube from the body,remove the fuel line from the lift pump and the return line from the closest joint and unhook the electrical connection for the gauge along the frame.
Then remove the bolts from the straps that support the tank-it will be very heavy if there is a lot of fuel in the tank.