Short rubber fuel lines

[tequilaiam]

Hello,
Are the short lines between the tank and the steel lines a common place for air to enter the lines? I have clear hose under the hood and I see bubbles rising to the input of a spin-on filter. I thought I saw bubbles where I have an electric lift pump down on the frame rail but haven't been able to re-create the issue in the garage. It seems to only happens on the road after only a few miles but can idle in the garage just fine.

Also could someone help me figure out the -34p manual? I'm trying to figure out what diameter fuel hose is used between the tank and the steel lines. Manual says to make it out off 9439068 , 9439128 and 9439010 but I can't figure out what this actually is. Guessing it's common fuel hose but the diameter isn't listed.

Thank you!

 

[Cory1337]

I replaced my lines from the tank to the frame rail, getting rid of the steel lines across the back of the cab. I had the issue of the truck was hard to start, and then one day it died on me on the road, so I started tracking down possible points of failure. You'll need 3/8in and 1/4in.

 

[cucvmule]

Air bubbles will enter from fuel slosh in the fuel tank just from operating the vehicle. However the more fuel that you keep in your fuel tank the amount of bubbles will be reduced somewhat, as less fuel in the tank the line will suck in more air bubbles.

Safety concerns are the reason why steel line is used and rubber sections for area's of movement, forces of vibration or twisting of the frame and Road Hazards. In my experience the more rubber line used the more problems that develop from the deterioration of the rubber clogging the filters.

If I have to replace a bad steel line I replace with a steel line if it is a permanent repair. Purchase the appropriate size steel line and a tube bender if you prefer a better tighter installation. Using the old line as a pattern is a good idea also. Sometimes a cutting and flaring tool is needed if you want the exact fit, if you can not find the right lengths of steel to work.

3/8th's inside diameter for fuel feed and 1/4 id for return line.