Gas leaking past fuel sender bolts

[NJ94Chim]

Argh!

I was getting a gas smell from my 94 400 every time I filled up. Turns out that gas was leaking from around the perimeter of the bottom of the fuel sender unit, and was also leaking out from underneath the bolt heads. This was despite the gasket being in Ok shape, and despite the bolts all looking like they were pretty firmly holding down the sender unit.

So i've now put in a new gasket, and have substituted threaded studs in place of the bolts. The studs make it easier to get the gasket and fuel sender back on. Plus I had to use a helicoli for one of the bolt locations in the alum collar was stripped. Since the SS bolts threaten to strip out the aluminum collar that the sender bolts down to, I figured with studs, I can install them once (with thread locker), so hopefully, they'll hold in place and not have to be removed again.

Anyway, the arrangement is no longer leaking past the gasket between the collar and the sender, but I am getting gas leaking past the nuts and washers that tighten down onto at least two of the studs.

Each stud has a rubber washer, then a metal washer, and then a nut. Clearly this ain't doing the job.

Is there maybe a better type of washer to use, or maybe I need to replace the fuel sender unit?

How can I seal around the 5 studs?

Thanks

[Belle427]

Seems a bit odd but maybe a suitable sealant before tightening the bolts?
Not sure which are compatible with fuel so you will need to check that, maybe something like hylomar will do.