QUOTE(jd74914 @ May 23 2018, 03:46 PM)
I might not be understanding what you're referencing, so ignore if you are taking about something different, but why do you think the threads on the M18-AN adapters are sealing? If it's still attaching to a non-tapered thread you technically need a sealing washer. I get that you can make it all seal up with some pipe dope, etc. but that doesn't make it correct on a straight thread fitting. Finding a fuel-compatible washer should be pretty easy if the supplied ones have compatibility issues.
I agree 100%... with the addition that we're installing two technically incompatible fittings. That adapter is not
designed to seal the way the original fitting is. So yes, you could find sealing washers. That's not hard, and if you think that's the way to go, I got nothing but respect for that. But that's also not the 'right way', IMHO. If I was gonna design this part to work 'right', I would spec a fiber washer (probably original) and CAD the fitting with the washer included to make sure there's enough threads to ensure correct crush of the washer.
I think it's presumptuous to assume that this fitting would seat correctly against a stock fiber washer in a way that would create a correct seal. Maybe it does, but I've seen enough adapters and 'custom' parts to be skeptical of making an assumption as big as that.
So rather than spending a bunch of time reverse engineering a stupid fitting, I just added a fuel safe sealant that has to stand up to 0 psi and seal a gap of around 0.01". I think Loctite 565 is well up to the task of those conditions.
But as I said, if you disagree or want to go another way, do it. Just report back here so we can all learn together.
(no sarcasm)