Brake Pipe Union Size

Yes, that looks just like the one on my Gen4.
I couldn't use these unions if I wanted, a brake flaring tool is one thing I don't have.

Forgot to say brake pipe needs to have a (double flare) for contact

Soeley, that is weird. Do Halfords sell female M10 x 1.25 fittings? to verify the standard JIM union size. I feel like there's a variance in the thread pitch. No way can the new 2019 Jimny have left the factory with imperial brake unions..

No, Halfords only list M10x1 male and female unions on the website. I am 99.9999% certain it isn't a 1.25 pitch on the male union.

Success, finally got delivery of more crush washers this week. Just tried the front passenger side and the new pipe went on smooth as silk.
Now to do battle with the drivers side, now I know the Goodridge pipes are all well and good.

So it turned out the union on the drivers side must have been damaged on assembly. Luckily I had some dies for a die head, these are actually M6x1, but with the pitch being the same was good for cleaning up the thread along with a ratchet Spanner on the union. After cleaning up the thread it screwed in by hand as it should.