How can I stop diesel leak at sender unit?

[MBWhite]

Put me down as a believer in Permatex #2 (the "pli-a-seal" stuff and not the #1 "hard-n-fast" stuff) for sealing plastic tanks.

The other secret weapon to use is PVC plastic pipe primer to clean and prepare the plastic surface, especially when using an adhesive on ABS.

When using a larger self tapping screw, if I have a choice I prefer to use one that has a 1/4" hex head and put it in with a socket and ratchet. Easier to go in and much easier to remove in the future.


Good luck!

[hamburking]

Lots of good suggestions here.

In the meantime, a diaper and masking tape might hold you over till a better fix can be done.

If there is diesel fuel present, no sealant will stick.

[leftbrainstuff]

Originally Posted by hlev00

I have a plastic diesel fuel tank that has developed a leak at the sender. The problem seems to be caused by one of the screws that has stripped the hole in the tank and won't bite. Other screws are secure. I saw some suggestions of creating a backing plate but I'm not in a position to do that at this point so am looking for an interim solution.

I am thinking of
1. Using a small amount of 4200 to seal the screw hole.
2. Apply 4200 around the sender to seal the leak between the tank and the sender plate.

Is 4200 the right stuff to use? Will it seal from the outside? I'm concerned about the 4200 coming off the screw and ending up in my fuel line, though hopefully the primary filter would pick it up.

Do you have any other alternative approaches?

Thanks,
Harry

The best repair for a poly tank is welding.

The second best is a compression seal with backing plate.

Goop repairs of poly tanks with diesel present almost never work or last. If the leak is on a flat area then option 2 works well.

Unfortunately Murphy's law ensures the leak is located such that option 1 is required.

Poly welding is easy. Heat is needed but not an open flame. Cleaning the tank is not.

A self tapping screw and diesel compatible gasket cement might work as a field repair.

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[sanibel sailor]

Hot melt glue gun for welding.