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Weeping fuel lines

4552 Views 10 Replies 7 Participants Last post by  sleeping giant
Well after about six months of burning B-100, my rubber fuel lines (as predicted) are weeping copious amounts of bio-diesel. I'd like to replace them with synthetic. Anyone ever changed all their fuel lines before? Any advice or instructions would be greatly appreciated.
Just in case anybody is wondering my truck is otherwise running very nicely on 100% bio-diesel which I purchase at the pump of a local gas station. I drive up, fill up, pay up, and drive away with a much cleaner burning fuel that is American grown.:cool2:
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Diesel fuel hose

I have changed all my fuel lines using steel line and short lengths of fuel hose. I used the recommended fuel hose for diesel but I am unsure if it is fully satisfactory for bio-diesel.

The recommended fuel hose for in tank diesel use is SAE 30R10 which has the "special" coting all through the hose.
The recommended diesel fuel hose for outside tank use is SAE 30R9 (fuel injection hose) which is rated for 180 psi and has a thicker "special" coting to resist diesel fuel than the also acceptable SAE 30R7 (fuel hose) which is rated to 50 psi. The SAE number is stamped on the hose and the SAE 30R9 is CDN$4.50 per foot at my auto supplier.

The source of the above information is from Gates.
In Ontario Canada the fuel lines must be metal with no more than 1 foot of synthetic rubber hose at each junction to pass a "safety". The feed line is 3/8" from tank to filter. The return line is 1/4" from tank to injector pump.

So you need a foot of 3/8 and 1/4 from the fuel tank sending unit to the frame (mine started a little longer for ease of installation) where 3/8" and 1/4" steel lines can be routed to within a foot of the mechanical fuel lift pump. Connect 3/8 hose to the pump inlet and 1/4" hose to the injector pump metal return line just above the lift pump.

The output from the lift pump is metal and is routed up the front of the engine and under the intake manifold, exiting near the fuel filter on the bulkhead. A foot of hose is more than enough to reach the filter inlet. I put 2 hose clamps on every connection.

You will need 3 feet of 3/8 hose and 3 feet of 1/4 hose. I do not know how much steel line I used, maybe 12 feet of 3/8 and same of 1/4.

You may also want to replace the hose from filter to injector pump and injector pump return hose to steel return line. Then you only have the 1/8" injector return lines to worry about failing.
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