Fuel leak tunnel line to fuel pump

[WERK I]

Happy 4th everyone!

Noticed a fuel smell when I parked the car this morning. Checked underneath a saw a drip, drip, drip coming down from the transmission cross-member. Quickly got it home and put it on the BendPak and found this.




The circled joint looks like the pressure side of the line, not the return. The leak also stops when the engine is off. So, which do you think it is; the tunnel line or the line that goes to the fuel pump from the tunnel line joint?

[kojo911]

my guess is the flex line fitting. The hard lines that run through the tunnel (on my car) have a threaded end with a AN or DIN (??) fitting. More likely the swedged in side on the flex line. That would be best case scenario, if it is the hard line that runs through the tunnel it's a major PITA. Also, the hard lines, to the best of my knowledge are no longer available, so you have to make new ones out of aluminum or braided line.

[JFairman]

Looks like it's leaking at the fitting that connects the rubbber line from the fuel pump to the line going through the tunnel if it's the supply line.
Can't tell from the picture but if it's the return line, same diagnosis.

You could loosen it and retighten it and see if that stops the leak or else replace it.
If you have a local hydraulic hose shop that can make you a new one after you give them that one so they can match it up that would be the best way to go.

If it's the return line you have to remove the line at the tank and quickly plug it with a cap nut. Or use a fitting with a piece of blocked off hose on the end or something.. or drain the tank first.

If it's the pressure line that has a banjo fitting on the other end at the fuel pump check valve (for CIS) you can clamp the rubber fuel supply hose going from the tank to the fuel pump with a folded rag and needle nose vice grips to clamp off the fuel goung to the pump. If that hose is old and dry rotting it should be replaced. That takes draining the tank or taking a dangerous shower/bath in gasoline while you do it.

edit: Just looked at your picture again and that's back by the transaxle. I was thinking up by the steering rack before. Anyway, you have the idea of what to do now.

[WERK I]

Thanks for your replies.

Looks like I'll have to drop the transmission cross-member with a support under the transmission, disconnect the throttle linkage, to get at that fitting.

btw, the drip comes from the front of the nut(towards front of car). It would be great if the fitting came loose, but hard to imagine a fitting comes loose after 29 years of use. Trying to remember if that tunnel line is a hard line all the way to that fitting. You guys remember?

[WERK I]

Originally Posted by JFairman

Looks like it's leaking at the fitting that connects the rubbber line from the fuel pump to the line going through the tunnel if it's the supply line.
Can't tell from the picture but if it's the return line, same diagnosis.

Ooops! Rotated the image to its correct orientation.

[kojo911]

the factory line in the tunnel is a "hard" one. I think oem is plastic but they are NLA. Do a search on hard fuel lines or tunnel fuel lines there are a number of options but you basically have to fabricate them. I used 3/8ths aluminum line w/ -6 flare at either end it was a PITA to get them in. Others have used -6 braided or teflon line but it is a tight squeeze.

[WinRice]

That's got to be the short rubber line from rear pump to hard line.

It's hard plastic line from the rear fittings to the front through the tunnel, then short lengths of rubber flex with crimped couplings to the hard line then to the tank and pump. They are pretty easy to pull out and put back. Disconnect at the rear, tie a pull string/wire to the fitting and pull out through the front. Use the pull string/wire to pull them back through starting at the front.

The hard lines on my 86 were in perfect shape and would probably go another 20 years. Really good stuff. All the soft lines on each end were in bad shape, so inspect the front lines while your there.

Surprisingly, the fittings all broke loose very easily.

Somebody here on Pelican makes up new ones, forgot the name.

[WERK I]

According to Pelican Parts the two hard lines are available, although the return line is special order. For '85 930(same part # for 930 '87-89);

Pressure Line (item 37) 911.356.066.07 $87.50
Return Line (item 43) 911.356.062.07 $116.50 Non-Refundable Special Order





Pelicanite 'BoxsterGT' has been making hardlines. I sent a pm to him about doing 930 hardlines.

[66cal912]

All of these lines are available or superseided. Including the hard plastic ones I ordered all of them through Pelican last year. Some came from germany. expect to pay around 800 to 1000 all Porsche parts not after market. pull the hard plastic lines out from the front after you pull out the front fuel pump. the hardest part is cutting out the isolating grommeta around the hard plastic lines. look at the cost as insurance. whats a thousand bucks on a 30,000 + investment.

If you want more details on the removal and replacement let me know.

Ben

[jsveb]

Whatever pelican cant supply, I bet you can get from Len, BoxsterGT. he is a fellow pelican. I have used his services with great satisfaction.

Send him and email and check out his website:

Porsche service repair Auto Sport Engineering - Stow, MA

[WERK I]

Jesper,
I have been in contact with Len. Unfortunately and unluckily for me, he does not have the specs for the lines so this would be a "first-timer" for Len. He suggested I send him the pump-to-tunnel line and CIS-to-tunnel line so he can fab the correct ends for the pressure and return lines.
I'm going to email Len again and ask if he's done '87-'89 lines. They're the same part number, so maybe there will be hope after all.

[WERK I]

Update:
Well, I was wrong....again.
Man, those tunnel lines are rugged.

The leak was in the crimp on the fuel pump side of the line. Lan Cummings (BoxerGT) of Auto Sport Engineering in Stow, MASS came to the rescue and fab'd a new for me. I provided the length of the fuel pump line and he quickly got it out priority mail so I could get to Road America that week.

Thank you Len! When I drop the motor this winter, I'll send Len the lines so he can use them as templates for future builds.