Fuel Tank Plumbing

911T1969 · 09-10-2008, 08:40 AM

I have a 1969 911T. It was restored by the PO in 1988. I am wanting to replace the rubber fuel lines running from the tank as preventative maintenance. It has a single line running to the engine compartment to a Hardie pump and Weber carbs. The lines there have been replaced.
I crawled under it to take a look. Looks like the PO replaced the tank to a newer version from a '79 or '80 according to diagrams in the Porsche PET. Refer to the above diagram. Supply line #31 is there, but capped. It just hangs loose. Of course, there is no pump #21 in place. The red return line is there, but it is used as the single supply line going to the engine compartment. It has a threaded fitting on the end and screws tight to the tank. The other end of the red line was cut and slipped over the hard line going to the engine compartment and collared.

Questions:

1. Fuel filter #19 drops from the bottom of the tank. Does it only filter fuel coming through supply line #31? Since my current configuration uses the return line as my supply line, is the fuel being filtered?
2. The red line going from my tank slips on the hard line going to the engine and is collared. Pelican shows this as a one piece $93 part! I just need the fitting and short section of rubber line replaced. What is the thread size of the fitting? could this be made?
3. Should I use line #31 as my supply line and cap the return line male fitting on the tank? If I do, the line coming from the tank has a bigger O.D. than the hard line running to the engine compartment. I would need adapters. Thoughts?

Thanks,

berettafan · 09-10-2008, 09:04 AM

I just pulled the rubber i wanted to replace, took it to the auto parts store and asked for several feet of each.

I did notice the hard line exiting the tunnel in the rear was a larger diameter than the hard line that runs into the engine compartment. lots of cussing took care of it. lord did i cuss. i mean really, keep the kids away kinda cussing. god that was awful. hateful. somehow managed to disconnect or bend the hand throttle in the process. damn.

>>>>>>>>>>>>>>>>>sinks into a fetal position in the corner sobbing uncontrollably<<<<<<

berettafan · 09-10-2008, 09:05 AM

oh, didn't have any threaded fittings. sorry i couldn't really help just needed some group therapy.

ossiblue · 09-10-2008, 10:14 AM

Can't help on the threads but there were some photos posted a few weeks back by someone who cut open a later tank to show the "bowl" that swirls the gas from the return line. It appeared that the filter only applies to the feed line so in your case, the "supply" line is not filtered. If that is a concern to you, you could follow your idea of swapping out the supply connections and fab an adaptor to the engine compartment, or you could possibly simply add a filter somewhere along the current set-up after it exits the tunnel if there's room. I assume there already is a filter someplace before the line enters the fuel pump.