Jim Smith,

I think at highway speed you will use about 2 gallons per hour (I don't know of any MB Diesel that gett 60 MPG), so you calculations are off by 50%.

Also, the IP does not get air bound. The over flow is at the top of the IP and any air goes out there and back to the fuel tank as long as fuel is being pumped to the IP. Any air in the lines goes out the bleeder hole in the in the top of the secondary fuel filter. If the hole in the fuel line is so large that air is sucked in by the fuel pump instead of fuel, then fuel starvation to the fuel pump is the problem.

P E H