How hard is it to change the fuel lines?

FenderGuy · 09-22-2006, 09:34 AM

Just got off the phone with Don Jackson Porsche. DJ said my fuel lines are leaking in the front and they would need to be replaced.

Says its a 5 hour job, but they dont have the time today...He said I could do the job myself if I wanted to tinker with it...

I say yes.....how hard are they to change out?

David · David's Garage

I've done two cars. As far as difficulty it's not to bad. Don't have the kids around though because there's lible to be some cusing. I highly recommend you do it, the two I changed looked very bad. And change both lines.

Procedure:

Removing the old fuel line:
1. Have a big fire extinguisher ready, really!! This is not a suggestion!!
2. Support the transmission
3. Remove the rear sway bar and front transmission cross member.
4. Looking at the two fuel lines coming out of the rear bulk head on the driver's side of the shift rod, the one on the driver's side is the return line, the one on the passenger side is the pressure line (CHECK yours’ and make note if they’re different!!). Disconnect these lines. It takes a 17mm and 11mm, although I used vice grips on the 11mm flats since the wrench was slipping. Have a catch pan ready for the fuel.
5. Go inside the car and remove the panel under the pedals, the gas pedal, and the panel over the shift coupling. (A good time to rebuild your pedal cluster)
6. Using a screwdriver, push out the rubber grommets where the fuel lines go through the front bulkhead from the inside.
7. Slide the driver seat forward and remove the shift coupling cover on the rear floor. Push out the rubber grommets where the fuel lines go through the rear bulkhead from the inside.
8. With the foot pedals were removed, look through the exposed tunnel with a mirror and light so you can tell how the lines are routed in the tunnel. Pull the hoses out of the tunnel from the outside the front bulkhead, they should pull out pretty easy.
9. Prepare a hose and bolt plug for the return line. Remove the fuel line fittings at the fuel pump. Have a catch can ready, mine only let out a little fuel and stopped.
10. Pull the line from over the steering rack. It's a little difficult getting it through the metal guide above the steering rack but a good hard pull should do it.

Parts needed:
1. Fuel lines, Check the PET.
2. Four, C-356-202-03 (Rubber Grommets)
3. One, K-134-018-02 (12mm Hollow bolt since your installing a 930 line not the 10mm original line)
4. Two, N-013-812-2 (12mm sealing rings)

Installing the new one:
1. Put a piece of tape over the ends of the fuel lines to keep out dirt.
2. Have a helper feed the return fuel line (I’ve never managed this without help) in from the front bulk head on the driver’s. Pull up the carpet in front of shifter console and help guide the fuel line through the top of the tunnel on driver's side as your helper feeds the line. You may need to remove the emergency brake cover to help feed the line through the tunnel. A mirror, light and guide stick help with getting the line through the correct loops inside the tunnel. If the engine’s out you can help guide it from the shift rod hole
3. Go under the car and feed the front of the fuel lines back through the metal guide above the steering rack. Run the return line and then the banjo fitting pressure line. YES, IT'S POSSIBLE. Attach the return line and banjo fitting with the new bolt and washers. When tightening the bolt, be sure not get the hose in a bind.
4. Slide the new grommets over the line at the front and rear bulk heads and push them in from the outside. Use a liquid silicon lubricant or silicon spray and a screwdriver.
5. Attach the lines at the rear and put everything back together.

47silver · 47silver's Garage

when you pull the old ones out tape/tie a strong string to the one end so that you have a pull string to help pull the news ones back through.

FenderGuy · 09-22-2006, 10:58 AM

Thanks for the words of advice

FenderGuy · 01:01 PM

Quote:

Originally posted by 125shifter
I've done two cars. As far as difficulty it's not to bad. Don't have the kids around though because there's lible to be some cusing. I highly recommend you do it, the two I changed looked very bad. And change both lines.

Procedure:

Removing the old fuel line:
1. Have a big fire extinguisher ready, really!! This is not a suggestion!!
2. Support the transmission
3. Remove the rear sway bar and front transmission cross member.
4. Looking at the two fuel lines coming out of the rear bulk head on the driver's side of the shift rod, the one on the driver's side is the return line, the one on the passenger side is the pressure line (CHECK yours’ and make note if they’re different!!). Disconnect these lines. It takes a 17mm and 11mm, although I used vice grips on the 11mm flats since the wrench was slipping. Have a catch pan ready for the fuel.
5. Go inside the car and remove the panel under the pedals, the gas pedal, and the panel over the shift coupling. (A good time to rebuild your pedal cluster)
6. Using a screwdriver, push out the rubber grommets where the fuel lines go through the front bulkhead from the inside.
7. Slide the driver seat forward and remove the shift coupling cover on the rear floor. Push out the rubber grommets where the fuel lines go through the rear bulkhead from the inside.
8. With the foot pedals were removed, look through the exposed tunnel with a mirror and light so you can tell how the lines are routed in the tunnel. Pull the hoses out of the tunnel from the outside the front bulkhead, they should pull out pretty easy.
9. Prepare a hose and bolt plug for the return line. Remove the fuel line fittings at the fuel pump. Have a catch can ready, mine only let out a little fuel and stopped.
10. Pull the line from over the steering rack. It's a little difficult getting it through the metal guide above the steering rack but a good hard pull should do it.

Parts needed:
1. Fuel lines, Check the PET.
2. Four, C-356-202-03 (Rubber Grommets)
3. One, K-134-018-02 (12mm Hollow bolt since your installing a 930 line not the 10mm original line)
4. Two, N-013-812-2 (12mm sealing rings)

Installing the new one:
1. Put a piece of tape over the ends of the fuel lines to keep out dirt.
2. Have a helper feed the return fuel line (I’ve never managed this without help) in from the front bulk head on the driver’s. Pull up the carpet in front of shifter console and help guide the fuel line through the top of the tunnel on driver's side as your helper feeds the line. You may need to remove the emergency brake cover to help feed the line through the tunnel. A mirror, light and guide stick help with getting the line through the correct loops inside the tunnel. If the engine’s out you can help guide it from the shift rod hole
3. Go under the car and feed the front of the fuel lines back through the metal guide above the steering rack. Run the return line and then the banjo fitting pressure line. YES, IT'S POSSIBLE. Attach the return line and banjo fitting with the new bolt and washers. When tightening the bolt, be sure not get the hose in a bind.
4. Slide the new grommets over the line at the front and rear bulk heads and push them in from the outside. Use a liquid silicon lubricant or silicon spray and a screwdriver.
5. Attach the lines at the rear and put everything back together.

How long did it take you to do this ? I'm planning for Friday after 6pm and Saturday and Sunday....

p911dad · p911dad's Garage

Fender Guy, I followed the procedure as per 125 shifter and 47 silver and although car is in pieces all over the garage, I successfully got the new lines in and re-coupled to the rear lines leading into the engine compartment. I decided to pull the tank and look it over and have it cleaned, so I went a little extra on the operation, although I will say with the battery out and the fuel tank out, it was easy to get to the front lines and really look things over. Using a strong nylon cord from the garden shed made pulling the lines through the tunnel relatively easy. I was relieved to see the rear lines looked like new, still with the shiny green paint on them and no corrosion.
The total time (this was the first time I have done this) will be about 10 hours, including the tank work and putting a new foam seal around the tank seam where it sits on the front floor opening. Total parts(all from our host) is around $230. I found a 12mmx18.5mmx1 meter piece of fuel hose for the connection between the fuel pump and the tank at international-auto.com(an Italian parts house) for $4.50, as our host did not have this part, or at least I couldn't find it in stock. You actually need 90mm of the hose, but I also used the extra length to replace a vent hose on the top of the tank. Remember, safety first! Good luck, Glenn

ruf-porsche · ruf-porsche's Garage

Quote:

Originally posted by 125shifter
Don't have the kids around though because there's lible to be some cusing.

Is there any job on German cars that doesn't have cursing?

I'm still cursing the BMW engineers for specifying shear bolts to secure the ignition / shifter interlock on my Bimmer.

47silver · 47silver's Garage

that is a tough job,,,nice work.

FenderGuy · 07:16 PM

Ok drove the car home from DJ's and the car did stink of gas....I did something silly, driving home I could feel my feet getting hot. I pulled over thinking the bottom was catching fire...Called DJ @ Don Jackson and he tells me he was checking the heat to make sure it worked....hell yeah it works it burned my feet

...washed the car and I am thinking I should change the lines a different time when I have more time and more tools (GF's stepdad doesnt have any jacks or ramps) ..I wont be driving it though untill the lines are changed... the valve adjustment made a difference it sounded nice and ready to rev harder

Don Jacksons shop is pretty cool..he had 4 cars on the rack...2 911s, 1 993, and 1 996 who blow a rod when being dynoed...

I'm in good hands if I ever go back to them...

Grady Clay · 09-23-2006, 04:02 PM

Bump

Let's expand this with some pictures.

What are the various choices for fuel lines?

Best,
Grady

Jeff Alton · 09-23-2006, 04:30 PM

125Shifter, very nice write-up! One for the arcives for sure. Nicely done.

Cheers

FenderGuy · 09-23-2006, 05:43 PM

Quote:

Originally posted by Grady Clay
Bump

Let's expand this with some pictures.

What are the various choices for fuel lines?

Best,
Grady

I would also like to know this...part of me not doing the job this week was DJ said they did not want to sell me the lines untill i know how much I needed? Or brough the used ones in? Can't do that or else I wont be able to get them in a easy manner I asked and he said they were rubber fuel lines....I might get flamed but will the rubber lines at AUTOZONE work?

Grady Clay · 09-24-2006, 04:45 AM

Here is the PET diagram for an ’80 911SC. Red #33 (911.356.060.05)
is the high pressure supply line and green #38 (911.356.062.08)
is the low pressure return line.
"

"
© Dr. Ing. h.c. F. Porsche A.G.

Are these assemblies rubber and plastic or rubber and steel?

This appears to be removed and installed from the front. An
easy installation tool could be made to screw on the rear
fitting. I think that thread is either 14x1.5 mm or 16x1.5 mm.
The tool can be made from an old fitting and nut with a long
semi-flexible plastic pipe. Simply tighten the fittings together
and pull the tool into the chassis when removing the old
pipe-hose assembly. When the tool exits the front, remove
the old pipe-hose assembly and tighten the new one to the
tool. This lets you pull (not push) the new assembly in the
correct location.

Installing these (or any) lines, great care is needed to not
stress, scratch, kink or otherwise damage the assembly.
This job should not be done in a hurry.

Four new #36 rubber grommets (911.356.202.03) should
be installed. Be sure to replace the #37 coverings
(999.613.015.40 or 911.613.017.40) also. Where does
#39 clip go?

Does someone have a throw-away chassis that can be
sectioned along the tunnel for images?

Best,
Grady

FenderGuy · 07:33 AM

Thanks all for the input

Thank you Grady for the PET pics, I was looking at them yesterday on my computer when I waa browsing through my PET

More and more its looking like a job for DJ. I hate to say that and would rather tackle the job myself. GF mom is complaing about my rear drip of oil

I'll head over to her house and get the motivation to buy some ramps and jacks and start on it (hopefully)

911quest · 09-24-2006, 10:08 AM

THe major diffence is between the 74-77 and the later SC because the fuel pumps are different the bango on the end is the difference between 10mm and 12mm

Grady Clay · 09-24-2006, 10:13 AM

Frank,

I’ll encourage you to do this yourself. This is one of those time consuming, simple appearing jobs that will start and stop when you run into a snag. The snags are likely to include having to revise your installation tool or finding something else in the process. A shop needs to keep working to completion. The best have all the tools or the ability to make something special and the space to have each mechanic working on several cars while one is waiting for something.

You can do this by not expecting it to be completed in five consecutive hours.

Another issue is replacing the original fuel pipe/hose assembly with something “of local manufacture.” You want this to be as good as or better than the original. That includes all the original engineering considerations of ease-of-fit, suitable materials, proper fabrication, longevity, corrosion and abrasion protection, and proofed to not be leaking.

If you are going to use a hose, I recommend you don’t have any connections inside the car. You are going to want to retain the metric screw fittings. This probably means you will want to fabricate the fittings at both ends of the hoses. A (local?) Porsche (or other German) dismantler is a good source for fittings. Go to some local hydraulic hose repair/manufacturer shops and discuss the issues. Their normal business is custom assemblies for fuel and hydraulic applications. They will also be able to proof-test the new assemblies.

Have you priced the OE Porsche hose-pipe assemblies? That also might be as suitable and economical.

Best,
Grady

911quest · 09-24-2006, 10:32 AM

I just replaced the feed line on my 77 the part from are host was 80.00 it took me about 2hrs. I used weed eater line taped to the end of the hose I had to drop the rear transmission mounts to get the other end of the line loose. I feed it thru as my wife pulled the line from the access panel for the shift coupler

Remember to secure the line to the old fuel line first so that it gets pulled back thru the same way and it won't get stuck on anything

David · David's Garage

Grady, I thought the OEM fuel lines were too nice to mess with. They aren't the cheapest way to go, nor are they the most expensive. I think I paid about $125 each when I did mine. Maybe a hydraulic shop could make them cheaper, but the spherical fit Porsche fittings seem pretty unique.

Of couse the way Porsche is with parts these days, we're probably going to have to find an aftermarket source.

beamonk · 09-25-2006, 06:28 PM

Who has made/run steel braid lines for this application?

David · David's Garage

On my current 930 project I used braided steel for all the lines except for the two lines through the tunnel. I certainly could have used braided although it would have cost more than the expensive OEM lines. The stock lines are well made and they fit.

BTW, I won't use braided steel lines again. There are better options now.