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A quick post to describe my fuel line replacement with an aftermarket flexible hose.
The 2 hard lines that feed from the pump and return excess fuel to the tank run the length of the car. They run from the pump well under the central tunnel and up behind one of the rear shock turrets into the engine bay. Unfortunately 2 things can fail, firstly there are 2 short lengths of rubber hose crimped to the line ends that perish and secondly where the hard lines (steel) turn up and over the rear shock they are exposed to salt spray from the rear wheel.
My supply line had rusted almost all the way through at the exposed section, worse where the line has sharp bends in it. It had also badly perished rubber at the engine bay end.
The replacement hard lines from Porsche are difficult to fit at home as they are all one length and have to be "threaded" up behind the shock/arb. This is if you can find any as they look to be NLA now. So I went for a flexible aftermarket line with a PTFE inner, braid and plastic coating. AN6 size.
I cleaned up and painted the return hard line as it wasn't as bad.
I looked at the pump and engine bay end and decided to delete the hard pipe accross the back of the engine bay. This hard line would be difficult to connect to (Metric female) and was just extra weight! I fitted an AN6 adapter to the fuel filter and ran the hose all the way to it.
Some pics..
Banjo to AN6, AN6 90deg fitting
Run in existing clips with cable ties to help
Up over the shock turret (this is the most difficult bit to bend and form the hose to fit)
Accross the back of the engine bay at high level using existing fixings and stainless P-clips
AN6 to metric adapter in fuel filter (I will move it to the new filter if/when I need to change the filter)
Last edited by tdiquattro; 03-27-2015 at 04:41 PM.
Oh and to connect to the pump you will need to hold the inner nut still and undo the cap nut on the end of the pump outlet fitting, to hold the inner nut still you will need to make something like this.... 17mm ground down.
(You can see the inner nut in centre of the first pic above, and the cap nut to the left, obviously you will need a couple of copper washers as well)
Last edited by tdiquattro; 03-27-2015 at 04:48 PM.
Thanks for posting.
So, just replacing with flexible hose front to back sounds like it works fine and is probably much easier to fit, instead of trying to thread a pre-formed steel line into the back of the car. And its cheaper and won't rust..seems like a win-win. Happy days!
Thanks Rob, the biggest shock was the state of the flexible rubber end in the bay!!, I bet there are a few like that - an accident waiting to happen. Thanks for your advice and inspiration as well!!
Good luck Johnny, just PM me if you need any more info
Cheers Nigel, this is on my list for the coming summer. I had to replace the clutch hardline and that was a right bu@@er to manipulate into position, and that put me right off the hardline fuel lines.
Did you spot any additional complications if the return lines needed doing as well?
Hi Nate, my Targa is back on the road, hope to make one or two of the uk meets soon
I think another run in the same type of hose for the return would be best, although it may not need it for the pressure this hose is good at self supporting along the runs and very tough with the stainless braid and coating.
It would need a bit of investigation over the tank and engine bay end connections, but there are plenty of connectors to choose from.
Came across your thread while trying to figure out the fitting sizes on the fuel filter. Do you happen to remember if it was the M10 x 1 or 1.25? You wouldn't happen to know the size of the other end of the fuel filter as well would you?
Came across your thread while trying to figure out the fitting sizes on the fuel filter. Do you happen to remember if it was the M10 x 1 or 1.25? You wouldn't happen to know the size of the other end of the fuel filter as well would you?Thanks.
Old thread I know, but FYI to anyone else searching for this info. The female thread in the actual body of the 964 fuel filter is M14 x 1.5 on both ends. The steel fuel lines coming into and going from the fuel filter use male and female fittings of M16 x 1.5. Of course the filter has adapters screwed into the filter body to go from M14 to M16.
I know this thread is very old-
but lots of information here. Looking to replace my fuel lines for piece of mind as I always have this in the back of my head when I am driving. Call me crazy.
Does anyone know how long these hoses are? Thinking that once I inspect, I'll upgrade the ones in the engine bay, just wondering how long the hoses will need to be.
Thanks again tdiquattro for putting this up!
Anyone considering going to an in-tank fuel pump to replace the original external pump when you do the lines? I haven't taken any *real* steps that way yet, as my lines and pump are currently still good enough. However they are all stock and will need replacing soon enough. Considering whether an in-tank system might simplify the fuel system overall - would need to make custom lines but one unit might be able to replace the separate pump, sender, and tank venting. Maybe get rid of the expansion tank also and just plumb a vent to the charcoal canister like in the newer 911s.
Just spitballing for now but this is one area that seems to be a regular problem spot, unnecessarily complicated, and not critical to the character of the 911. Although I guess *some* oil and gas smell is characteristic
Old thread, but since I just finished this, there's a few things I can add to help others:
Fuel pump to engine bay used about 14 feet of line (I ordered 20 ft but didn't confirm length and measured 6 ft left over). This is on the long side, but you might as well replace the short hardline as well and if you're like me, you may break a fitting or two so the extra foot or so helps.
I couldn't find an AN6 to M16 adapter that was properly flared on the metric side. So, that means you need to get a seal somehow. I think the appropriate method is a copper crush washer, but someone can correct me if I'm wrong. Amazon has a set of sealing crush washers in all metric sizes for cheap, like $20
For the fuel pump fitting, I used a U turn 180* fitting. I originally did a 90* but it put the line below the body regardless of how I oriented the fuel pump. 180* is what the soft line was so this works well.
You technically are probably supposed to drain the tank when you disconnect the banjo bolt at the fuel pump but I found that a pan below and working quickly, you make a mess but only lose half a gallon at most of fuel. I believe fuel stops coming out of the pump once the banjo bolt is removed.
Overall, this was a pretty easy project. I think it took 4 hours since I had the engine out. The only challenging part is getting the hardline out over the brake lines. If yours is shot, just cut it rather than try to fish it through.
remove fuel: loosen the line between fuel-filter and rail. Used one of the AN-> Metric adapters and create a dash line. connected this line to the filter and the other end to an can (i had this can outside the garage) and then short-cutted fuel-pump over the relay socket... Took me 10min and was completely clean and save doable...
03-27-2015, 04:13 PM
Fuel Line replacement DIY
