Fuel line leak resolution???

[MattAlpha]

I was doing a little maintenance to my supension last night when I smelled fuel. So I looked around and saw a small dried up puddle on the top of my splash/belly pan. So I finished up the supension work and called it a night.

This I took a look at the tech articles and few searches on replacing the fuel pump, since I assumed its seal were seeping fuel. I took off the pan a few minutes ago and did find much. So I started (while still on jack stands) and run it for about two minutes, this is what I found.

It seems that I have two fuel line leaks off of my fuel pump.

Does anyone know who I should go about fixing this? It seems the line that supplies the engine's fuel filter is the culprit.

Here are some pictures:






I found this one as I was getting out from under the car.


Any advice or suggestions are appreciated.

BTW, the car is now a garage queen until this is solved, it was my daily driver.
-Matt

[HarryD]

You need to determine if the leaks are at the metal to metal joints or where the rubber meets the metal fittings.

It could be as simple as replacing a crush washer (metal to metal joint)or as complicated as removing the line and replacing it with new (or take the leaking hose to a hose shop and have them crimp on new hoses on to your fittings).

I am guessing the latter.

[p911dad]

Matt, those look like the original lines, and will probably need to be replaced. The job is a bit**! However, you are dealing with gasoline under pressure, and safety is paramount here. Our host sells the OEM lines. They run through the tunnel and connect to the rear engine fuel lines over the transmission. There are several very good posts in the archives, if you look under fuel lines you will find them. The parts are around $300., and the time is at least 10 hours if it is the first time you have done it. Good luck Glenn

[MattAlpha]

Thanks guys for the advice.

So it looks like a fun process is ahead of me....


Does anyone know if the fuel lines in that go through the tunnel (the main culprit is the supply line) are the same for SC and Carrera models? If they are different then I'm going to have the fun of determining which one is currently installed.

Thanks,
Matt

[boyt911sc]

Matt,

The fuel line (replacement) for SC is not exactly the same as the old ones. Porsche has changed the banjo fitting shown in your picture to a larger one 2 mm bigger. Unless you could still find the older model fuel line, you could still use your old hollow bolt/check valve.

When my new fuel lines arrived from Germany, I went back to the Porsche dealer and complained about the bigger banjo fitting. And showed them the old fuel line with smaller banjo fitting. It turned out that the old fuel line from the fuel pump has been superseeded by a new fuel line with bigger fitting.

The banjo fitting changed from 10 mm to 12 mm (similar to '80 & up 911 Turbo).

Tony

[HarryD]

Once again, when you get the old line out, the metal line and fittings should be fine, you will just need to replace the rubber parts. Any decent hydraulic hose shop can swedge the hoses onto your hard lines and fittings. If you are worried about leaks, don't be. The guys in the hose shops build lines for 10,000+ psi lines. Ours are child's play in their world.

[MattAlpha]

Harry and Tony thank you for your advice.

I took a look at the fuel lines and associated hardware on the new diagram pages that Wayne has added (a great resource for me). Which helped me determine that I do have the original fuel lines in there and that they are of the '78 vintage.

Does anyone think I'll run into problems switching to the later SC/Carrera lines?

If I can find a hydraulic shop in this area then that would be the cheapest route. I have experience with them from my first ship (Navy wise) and I agree that the psi level of our fuel lines are much lower than their capability. Do my swedge ends look like they're in good enough shape to be re-used?

What other stuff should I purchase from our host? I've already added 4 rubber sleeves and 2 rubber mounts to my cart. I'm looking at new sealing rings and possibly a new retaining valve.

Thanks,
Matt

[MattAlpha]

I want to thank everyone for your help with this problem.

I corrected this issue last Tuesday, but I was way to busy constructing and putting my subframe in update this post.

I ended up using the Walt Fricke method to replace the rubber section. The rest of the "hardline" was in perfect condition and it would have taken more than a week to receive them from our host. So I ordered all of the seals that I needed from our host and they arrived the next day!!!! Great job Pelican Parts, thank you!

I used my dremel to cut off the old crimps. A very easy task since they rotate on the fuel line (which I didn't realize at first). I used two hose clamps because none of the hydro shops in my area did hoses this small in diameter. I also couldn't find the exact hose diameter that I was looking (no shop carries metric hoses) for so I had to settle with 3/8". It still fit snuggly over the fittings.

Here are some pics of the process:











On a side note, make sure that you buy both seals for the banjo fitting and also the seal that goes in between the check valve and the fuel pump. When I started taking off the nut that secures the banjo fitting my wrench slipped off of the check valve and onto the fuel pump the instant the nut gave way, thus seperating the check valve as well. I was lucky that I had ordered that seal as well.
-Matt

[MattAlpha]

Another thing that I did "while I was in there" was to replace the rubber fuel pump mounts. This was much more painful than replacing the fuel line because it is so hard to get the correct angle on the top mounts bolt, but with some paitenance and effort all went well.

Here are a couple pics of the old mounts and the new mounts.




Since replacing them I feel that my fuel pump is in better hands down there and I've noticed that its a bit quieter, at least the pitch has changed.

Hope this helps someone,
Matt

[88911coupe]

Any tricks to working in the area? I had to work up some sort of patch but my car's in hibernation for a rebuild and this is one of the jobs I wanted to tackle. I recall it being difficult to get in the area and access anything. Did you remove anything? I'd like to avoid removing the front suspension if possible.

[DW SD]

I would caution you on the use of the hose clamps you selected. You can buy non-abrading clamps which will not cut into the fuel line when clamped. These are safer. Buy genuine NORMA clamps, which come on Porsches (at least older vehicles) or buy fuel injection clamps from a reputable parts source. You'll see that the metal clamping surface is flat with no slots on the higher quality clamps.

I have bought nice ones from the Porsche dealer and the Mercedes dealer. (no more than $2 / clamp.) Also, it is standard practice in some applications to double clamp. Seing as you removed a robust swaged end, I may suggest double clamping with the high quality clamps.

The clamp in this picture looks like it might have been overtightened:

http://forums.pelicanparts.com/uploads10/DSCN69511182352029.jpg

Hope it helps. We want you safe and sound on the road, enjoying your vehicle and the new subframe.

Excellent work, by the way, you are making some nice improvements to your car.

Doug

[MattAlpha]

DW SD,
I will be switching the clamps over to the non-abrasive type. I was in a pinch at the time and they were out of the non-abrasive for the 3/8" hose clamps. I'll be putting some in when I do the return line and the supply line (off of the tank to the fuel pump) after I run the tank down. I had a full tank when this leak started and no where to store 19 gallons of fuel. Very good point and I'm glad that you brought it up.

88911coupe,
I had to remove my steering rack spacers (not applicable if your car is at US ride height) so I could remove the old hose and install the new one. Aside from that I did not remove anything else, and I didn't think it would have been that much easier if I had. I was very careful while maneuvering the dremel around, as I'm sure you can imagine.
Best advice that I have is to remove the banjo fitting first and drain the fuel out of the hose, after clamping the supply line to the fuel pump. After I drained that hose as much as I could into my fuel catch container. I cut the hose (as you see in the picture) so that I could remove it and allow me to rotate the other end that remained attached so I could cut the clamp off using only the dremel. I cut the new hose to the approximate length. I secured the banjo to one end and then routed/feed the hose to hard line end. After securing the bajo back to the fuel pump/check valve I cut the hose to fit exactly to the hard line. Then I installed that hose clamp and I was done. Pretty straight forward and simple.

-Matt

[88911coupe]

In looking at the picture am I correct in that the swaged fitting is not actually part of the banjo fitting...it's basically a short tube with one end rolled in and fits over the end of the hose?

[MattAlpha]

Buck,

You're right on. Its flared down onto the fitting and then crimped down onto the hose to secure it to the fitting. After a while the rubber degrades and/or shrinks and the fit is no long tight causing a leak to result. As in my case it started at both ends, just my luck.

-Matt