I have been able to seal a spun threaded insert with PC11 epoxy - never leaked a drop in many years. I was able to chip it off to examine the insert later, so it is a reversible fix.
jp 83 Euro S AT 57k

 

I don't know that the insert has spun but it is not evenly located relative to the tank sealing surface. Perhaps if I fill the crack with the PC11 epoxy and then file the sealing surface flat for the seal on the strainer it will be a long-term fix.

Another thought I had is to fill the crack with silicon RTV, possibly putting a bead around the insert also such that the seal on the strainer would compress it. Any thoughts regarding this option would be appreciated.

 

My 78 has that same crack/ split in it. I sealed with epoxy, allowed it to dry for a week and sanded smooth....that was in 2012, and no leakage yet....car is not driven tho, if that matters....I think it’s documented somewhere in my #30 revival thread....

 

Great, thanks for the input.

 

Don’t use rtv the fuel will eat it

 

After three failed attempts to resolve the problem I put the car away for the winter with the fuel tank empty.

The most recent attempt was using PC-11 epoxy in the area where the split was located and it visually looked good, but once I got it all back together and added a few gallons of fuel the leak was back. I didn't take it apart again but I am beginning to wonder if fuel is seeping past the insert to tank interface even though the insert does not appear to have spun/moved in the tank.

Hopefully next spring I will have a fresh attitude and greater success at fixing the problem.

 

I just went through pretty much the same issue. I can't tell from the pic you posted if the crack on the strainer outlet is only through part of the threads. You "might" be able to save it by pulling the metal threaded insert and getting the new insert from 928sRus (Roger). But even then, you will only have a little bit of plastic before the crack spreads into the main body of the tank, at which point you are screwed and will need another tank anyways. Look for a good used tank for the next couple months then install it before spring and be ready to hit the road!

 

Just looking at where that crack is, I'll speculate that it may be the result of someone trying to tighten the fitting to solve a dribble from a leaking rubber seal. The steel sleeve inside is drawn out into the formed end and stretches it to split.

For folks playing along at home, if you see a drip, dribble or film of fuel at the nipple insert where it meets the tank, the only direction you should turn that nipple is counterclockwise-to-remove. Replace the seal, and follow the WSM torque recommendation so you don't end up pulling the sleeve back in the nozzle and ruining the tank.

 

It is quite possible that the fitting has been over torqued in the past. I speculate that a previous owner has replaced the strainer because it was a Purilator rather than Porsche part when I removed it. That being said I have owned the car for for 14 years and this is the first year I have had a problem.

Finding a decent used tank for a reasonable price may be a challenge. I looked on 928 International's web site and a used tank is pretty expensive. I am not sure that removing the insert and installing the 928Rus replacement will work given the compromised tank in that area already. Given that the tank may be questionable I may try using a combination of PC-11 epoxy and the band clamp around the neck of the tank to seal and provide strength to the area.

If someone has a source for a good used tank please let me know.

 

I think the repair piece from our friend BauerR via Roger still needs to have that sealing face intact. In my one repair experience, we found that the inside of the plastic nozzle has assumed the crosshatch knurling pattern from the insert when it was molded. While I'm sure there was initially a pretty good seal between the nozzle and sleeve, Porsche still included the rubber ring against the end of the nozzle plastic to make the final seal.

In our local clinic fix, I put the original sleeve back into the nozzle with JBWeld epoxy, using an all-thread and washers fixture to hold it in place as the epoxy set up and cured. We didn't test the sleeve alone for sealing in the nozzle, instead assembling a new screen and fitting with a new seal, and fuel-proof thread sealing paste inside the sleeve.

Fast-forward to your situation. Would I try to set a sleeve in the nozzle the same way in epoxy and depend on it [read: guarantee it] to not leak for the remaining life of the car? No. I might look hard at the repair piece and see if there's a safe way to place a sealing ring at the end of the sleeve inside the nozzle, and another outside, so that they sandwich the damaged end of the nozzle. Still, whatever repair solution I came up with would need to pass the "will it burn the car and house down when it leaks?" test.

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In my little spare-time consulting gig in the power generation industry, I get to listen to some pretty amazing suggestions. Most are made in the heat of battle, when someone is trying to come up with that one magic-bullet solution to an otherwise very expensive can't-run condition. I try the "cost to not do it" vs. "cost to do it times a risk factor", and I can usually convince folks to avoid doing really stupid stuff. Once in a while though, when the decision process is spinning out of control, I pull out the "get a letter from your insurance carrier saying it's OK, and I'll do it." card. I can safely say that, in several decades now, no such letter has appeared. We need to use the same thought process. We used to ask 'What would Jim Bailey or Wally Plumley do?', in deference to some universally recognized expertise in such things. The guys with lots of available risk like Greg, Sean, Stan, Dave C, etc, will tell you what they and their insurance carriers consider acceptable risk. Carl can share more about the long-term effects of fire on his business, notwithstanding the damage to customer property. None of it is pretty.

 

Thanks Dr. Bob, point well taken.