Fuel leak at right sender

Found the area of the fuel leak (see image) on my 9a. Unable to tell EXACTLY where the leak is.

I am tempted to try sealing the screws, and see if this takes care of the leak. I gently tried to see if I could begin to pry the sender loose, without damage to the sender or the mount plate. Unable to even begin to pry it loose. The sealant is very sticky gray that is still pliable. One of the screws (top) has a brown sealant that is less pliable. Thoughts on sealing the screws, to see if this cures the leak?

Also, does the sender wire lug require a seal (i.e., o-ring) as part of the screw and washer assembly that attaches the wire eyelet? In other words, will the sender leak fuel through the screw hole in the wire attach lug if no steps are taken to seal the attachment?



Thanks,
Wayne
N1179J
Dues paid for 2017

Don't try resealing just the screws.

My best advice would be to remove the sender, clean everything up and reinstall using proseal only. No gaskets.

Use allen-head screws for the install. They are much easier to deal with in this area.

Second choice would be to remove the entire cover plate and do the same. The cover plate does not appear to be leaking,
but it would make the overall job easier. It's much easier to get the sender out through the bigger hole.

You might just try removing the screws one at a time and adding proseal to the threads and reinstalling. It looks like it is leaking through the screw holes. Use a screw that you will be able to get a solid grip on to remove if/when that becomes necessary.

After I did some research, this stuff:
https://www.permatex.com/products/gasketing/permatex-permashield-fuel-resistant-gasket-dressing-flange-sealant/

with no gaskets, has been sealing the flanges and screws on both my -4 tanks for a couple of years, now. I run non-ethanol premium mogas exclusively, unless traveling where I can't get mogas. I've had additional leaks at prosealed joints in the tanks, but the flanges have never leaked again. It remains soft and sticky seemingly forever, even to the point of being able to remove/replace the flange with the same sealant. I've had to go back into the tanks for proseal leaks, and it's a simple process to remove the flanges. No battling cured (and leaking) proseal to get the flange off; just remove the screws & apply slow steady pressure on one side of the flange. It's kinda like pulling your shoe off bubble gum, but less messy.

FWIW, YMMV, ETC

Charlie

Fuel sender leak

Thank you for your responses. I am thinking the screws are leaking. I removed all screws, so I am past the point of removing one at a time, as noted by one of the responses. I need to clean up the sender, and will try using the permatex product recommended. Will replace using hex screws as recommended in other discussions. If I use laquer thinner to clean up the sender, will it compromise the sealer between the sender and the rib plate? I want to retain the integrity of this seal, assuming it is only the screws leaking. Recommendations for cleaning up the sender (fuel dye and old sealant) would be appreciated.
Also, is there a possibility of fuel leaking through the threaded hole in the sender lug? It has A LOT of dye around it. Should this screw assembly be sealed with a small o-ring? Perhaps the wire attach lug is compromised?
Thanks, Wayne
N1179J
Dues paid 2017

I used the Permatex in the screw holes. I just put a ~1/8-3/16" bead over each screw hole & then torqued the screw.

Play with it prior to using it, to be sure you're comfortable with it. That method will leave a little ball on the end of the screw inside the tank, but they never seem to move. I've had the covers off since I started using the stuff (more proseal leaks) and the undisturbed spots were still there after a year.

You could probably get the same results with a bit more effort by putting a little donut around the screw's threads up near the head before installing each screw.