1994 F53 fuel lines

[subford]

I am a little confused here and need a little help.


It seems like all the Ford trucks I have worked on the supply line from the tank was the larger of the two fuel lines (5/16 & 3/8).


I looked at my 1994 F53 getting ready to do a modification to install an extra high volume fuel pump and the fuel filter is on the smaller 5/16 line. This does not seem right to me with the 460 engine. On all Fords the filter is on the supply line to the injectors. I do not want to cut the wrong fuel line.


What I am asking is the smaller 5/16 fuel line the supply and the larger 3/8 line the return on the 1994 F53?

[DriVer]

Quote:

Originally Posted by subford I am a little confused here and need a little help. What I am asking is the smaller 5/16 fuel line the supply and the larger 3/8 line the return on the 1994 F53?

subford, I have worked as a heavy equipment mechanic for enough years and during that time I had not seen an inline filter on a return line. In this case I would say with confidence that the line with the filter is the supply line!

[mpaton]

It makes sense if you consider the pressure in the lines.

The feed line has to make sure that there can be about 40 psi at all times, even with the engine guzzling all it can, the filter slightly used, and the engine higher than the fuel level. So I'd guess the pump probably puts out 60 psi or so.

The return line has to be able to have about zero pressure drop, even when maybe half of the supplied fuel is being returned to the tank, under not very much pressure. If there is pressure drop across this line, then the regulator won't regulate too well.

This is why some vehicles had multi speed pumps. For a 460, in 1p94, probably a big line was a lot cheaper.

Michael

Quote:

Originally Posted by subford I am a little confused here and need a little help. It seems like all the Ford trucks I have worked on the supply line from the tank was the larger of the two fuel lines (5/16 & 3/8). I looked at my 1994 F53 getting ready to do a modification to install an extra high volume fuel pump and the fuel filter is on the smaller 5/16 line. This does not seem right to me with the 460 engine. On all Fords the filter is on the supply line to the injectors. I do not want to cut the wrong fuel line. What I am asking is the smaller 5/16 fuel line the supply and the larger 3/8 line the return on the 1994 F53?