I have a 1988 F 450 Super Duty with an 11 foot utility bed on the back. It has the factory dual tank set up with one between the frame rails on the side and the other in back. Both tanks are hard to fill but the front one's nearly impossible. The filler hoses are fairly flat pitched and diesel foams so the pump shuts off unless I fill at an extremely slow rate. It takes me a good 15 minutes to fill the front tank. Anyone else have this problem and find a cure for it?

 

That is one of the problems with the stock set up.. I have a F450 with a stock front tank, between the rails, and an aftermarket 45 gallon tank at the rear.. Before I modified the set up, the front tank would only fill at a trickle.. What I had to do to rectify the situation was radical, but effective. I have taken the filler from the stock location, under the flatbed, and put it 9" above the bed, in a box at the very front of the bed.. I relocated the rear tank filler to this position also, and can now fill both tanks at the same rate. I also increased the size of the breather system, to 1" pvc pipe, attached through the overspill valve hole.. I fitted a 1 way liquid trap in the breather hole, to replace the spill valves on the tanks.. I have fast filling tanks, and the modification took a little over 2 hours, at a cost of $40 total. The modified piping was galvanised exhaust pipe, 2 inch diameter, at 1.75 a foot, with the join to the tanks being radiator hose, to fit..
I would post a picture of it, but the webshots system is dying by the look of it.

Wm
http://s2.webshots.com/icache/co/46/38/21954638hyIRLZnMLJthumb.jpg
'96 F450 White with Grey interior Crew Cab. Banks Turbo, Intercooler and Exhuast,
Power pack Chip, shift kit, Auxiliary transmission, electronic enhanced transmission control,
16 forward and 4 reverse ratios, 340hp 660ft lb 4 wheel drive, 12,ooo# winch

 

Just a thought, but galvanized pipe is not a good idea. I think it is incompatible with diesel fuel. If I'm not mistaken diesel will remove the galvanizing and either clog your fuel filter or may be so dilute that it will eat up injectors/cylinders.

 

After reading your post, I went to look, and 3 years into it's life, the galvanised tubing is still good as new.. No fuel remains in the pipe, it is only delivered to the tanks in it, so it seams to be ok... If anyone does this i would suggest stainless, in view of the possibility of galvanised pipe creating a problem.

Wm
http://s2.webshots.com/icache/co/46/38/21954638hyIRLZnMLJthumb.jpg White with Grey interior Crew Cab. Banks Turbo, Intercooler and Exhuast,
Power pack Chip, shift kit, Auxiliary transmission, electronic enhanced transmission control,
16 forward and 4 reverse ratios, 340hp 660ft lb 4 wheel drive, 12,ooo# winch

 

I've wondered why they use what appears to be galvanized filler opening, but then it could be stainless. I just remember that you are not supposed to store diesel in galvanized jerry cans and that is why diesel is almost always stored in plastic now. Anyone know for sure whether diesel will disolve zinc?

 

if the hose is pinched shut some there is not much to do except redesign but. try spinning the pump upside down then pumping your fuel. worked better on my last truck???

parts man

 

well by 1993 Ford still didn't improve the fill spouts much
My 93 fills slow too .. got an idea from a service attendant here in British Columbia.. they had a 6X6 with a tapered end to it that you drove your rear wheel up on.. worked good so when I got home I built my own from 3 pieces of 2X6 of 3 different lengths so to form a ramp.. I keep it in the box of the truck so I have it when I fill the truck up.. sure cuts down on the fill up time

hope this helps you out some

 

Talking to a guy at the service body repair and installation place I got told that there's supposed to be a smaller hose inside the larger outer hose that helps vent the tank as it fills. I'm relatively sure my diesel lacks an inner hose in at least the front tank. Anyone else know anything about this?