Fuel Lines Leakage at Fuel Pump

tiwebber · 07-07-2012, 05:11 PM

I have a 72 911e. Last time I started the car it was leaking fuel right below where the fuel pump is located. I have taken the pump out of the stand it sits in and am "trying" to get the lines off. They dont come off the pump easy. What I'd like to do it cut the lines at the lowest point possible and re-attach - for now. Then take the car in for a fuel line replacement. Does this sound reasonable? Do I need to clamp these lines first? I am guessing there can't be alot of fuel in the lines to the fuel filter but I just dont know if the line to the gas tank is "free flowing" or not.

Not long ago I had a leakage near the fuel filter - I was able to patch it up by cutting off the end of the line and re-attaching. I did take the car in at this time but the mechanic thought the lines looked fine. I guess when I cut the line it does sort of look fine. The rubber at the end of the cut looks fresh but I think replacement might be in order.

timmy2 · timmy2's Garage

Replace it with new e-85 compatible fuel lines. Better to be safe than sorry and watching your baby burn!

Porboynz · Porboynz's Garage

Clamp the lines with a pair of vicegrips, cut them, then plug them with a suitable bolt and hose clip. If they are that hard they will not come off the pump they need replacing. Only the lines to the fuel tank will dribble a lot of fuel and you can clamp them off at the front when replacing the rears.

silver911rdb · silver911rdb's Garage

Are you sure the lines are leaking and not the fuel pump itself. My 73 was leaking at the electrical connector. There is an o-ring seal within the pump that might leak with age.

tiwebber · 07-08-2012, 08:59 AM

Thanks all. i am not sure that its the fuel lines but i am pretty sure of the location of the leak. I assume you mean electrical connector on the fuel pump?

silver911rdb · silver911rdb's Garage

That's right, the electrical connector on the fuel pump.

silver911rdb · silver911rdb's Garage

Check out this thread...I posted a picture of my pump dismantled so you get an idea of what causes the pump to leak

Can I repair my MFI fuel pump

tiwebber · 07-08-2012, 02:46 PM

That picture does help - thankyou. My fuel lines are so stiff that I cant push them back on. what sizes do I need to replace them all? i seem to have two sizes, 6/10 (ID/OD) and 8/13. Is that correct?

tiwebber · 07-08-2012, 03:02 PM

That picture does help - thankyou. My fuel lines are so stiff that I cant push them back on. what sizes do I need to replace them all? i seem to have two sizes, 6/10 (ID/OD in mm) and 8/13. Is that correct?

tiwebber · 07-08-2012, 04:17 PM

Grady Clay gives qty estimates for Fuel Hose replacement in this thread

Braided Fuel Hose for a 72T MFI

chrismorse · chrismorse's Garage

Hi All,

Here is a shot of the fuel line on my 74 on ariving home - must have been leaking for the better part of the 500 mile trip. Notice the proximity of the fuel line to the heat dump valve.

This is the fuel line from the pump to the fuel filter. I have since moved the pump to the front and installed Strato-Flex heat shielding on the adjacent fuel lines.

Sorry for the hijack, but thought this hazard worth mentioning.

regards,
chris

tiwebber · 07-10-2012, 05:32 PM

Just received my replacement fuel hose. I want to start replacing it between the pump and the fuel filter and from the pump back to where it connects to lines that go inside the body of the car but I am not sure where I can clamp the fuel lines connected to the gas tank?

Thanks!

timmy2 · timmy2's Garage

If you remove the tank, all will be revealed... PITA but probably easer in the long run.

Porboynz · Porboynz's Garage

Or you could take a look behind the front suspension tube underneath and eyeball where the the fuel lines exit the tunnel and connect to the fuel tank. Alternately drain the tank first, good option to ensure filter screen in the tank fitting is clean, plus if its the same flexible hose up front like on my 72 then you want to replace that as well.