HPFP check valve leak

I've been battling a HPFP check valve leak - see pictures.
From dropping constantly and forming a pool on the gearbox I reduced it to barely getting gasoline moisture on the fingers when keeping them at the base of the check valve for 5-6 seconds.

What I tried:
(after removing the intake, battery etc to make space)
1. I tried to loosen the fuel hardline fitting (19mm wrench) while countering on the check valve (17mm), to clear the hardline and tighten the check valve separately then attach and tighten the line. It wouldnt budge now matter how hard I pulled, they were stuck, it started to deform the ridges (barely) of the valve due to the countering. They twisted together or none at all.
2. Managed to tighten the check valve by tightening the fuel hardline along with it with the 19mm as they twisted together. But soon I was starting to put stress on the hardline itself as it started to bend/twist slightly to accommodate the tightening.

Plan:
I decided to buy a new hardline and go to a shop to have them remove the assembly and put a new hardline in, although the old one is not leaking at all, it's stressed from the twist and might start soon. Or it might break during removal.
My question is what can I do about the check valve on the HPFP itself?

- Should I try just to tighten it further?
- Should I remove it and screw it back on with some smidge thread locker, teflon or liquid teflon?
I just worry that these things - the fitting, valve itself might go bad once they start leaking and you start to mess with them, as in never seal properly again.
I searched high and low and there's no separate check valve to be bought only the whole HPFP.
Another option is to purchase an used HPFP give it a clean and transfer the upgraded internals from my current HPFP.
Idd prefer not to do that if I can solve just the check valve issue. Maybe some people from here have more experience or encountered this and can give some advice. Thanks!

 

@Enki

 

Personally, I would remove it (dry it out real good, remove all the stuff that can be hurt by heat like the o-rings and whatnot), clean out the threads with a small wire brush and then reapply red loctite and reinstall. This thing sees high pressures and tightening the hardline may cause it to move, so using teflon tape probably isn't a great idea.

 

Thanks! I'll try that when the new hardline arrives.

 

when it comes to locttite the locttite 567 high temp thread sealant or permatex 59206 high temp 592 thread sealant is what I'd use as the permatex is specifically listed for fuel fittings

 

FYI in the worst case that you do have to go the new HPFP route.

Rock Auto has the Hitachi HPFP for about $300. Hitachi is the OEM manufacturer for the factory Mazda HPFP. I've been running the RA Hitachi pump for about a year now.

 

Ordered some loctite 592 as I can't find permatex here.
As for worst case scenario, thought about buying an used HPFP (as a cheaper solution), clean it and transfer the autotech internals from my current one.
That being said, I also saved the Hitachi HPP0027 on Rockauto, although it would go through the same process. Thanks for the advices!