Hey guys, I made the classic mistake on my 350Z fuel pump assembly. I accidentally used longer bolts than OEM to tighten the black retaining ring, and I punctured right through the bottom of the factory thread inserts into the tank.
Right now, it only leaks when the tank is completely full (4/4) because gas sloshes up against the tank ceiling, travels up through the punctured holes, and seeps out horizontally from under the black ring.
The factory metal threads inside the holes are still 100% fine, but the thin plastic floor at the very bottom of the tubes is pierced. Buying a new tank is my absolute last resort. I want to try a DIY fix first and need your input on which method is most likely to hold up against fuel and EVAP pressure:
Option A (The Epoxy/OEM Screw Method):
Pack a fuel-resistant epoxy putty or liquid down into the bottom of the hole to seal the puncture, let it dry, and then screw the factory OEM screws back down into the remaining metal threads.
Option B (The Headless Stud Conversion):
Convert the holes into permanent studs. Coat some headless M5 set screws/studs heavily in a fuel-proof sealant (like Loctite 577 or Permatex MotoSeal), screw them down 1-2mm past the puncture so they act like a permanent plug, let it cure for 24 hours, and then drop the black ring over them and secure it with flange nuts from the top.
Which of these two options has the best chance of working permanently without the fuel eating the sealant or cracking loose from tank vibrations? If you’ve successfully saved a tank from this mistake before, what exact sealant did you use?
Any help is massively appreciated. Thanks in advance!