Which brake hose into tee fitting configuration?

I'm probably overthinking this from staring at it so long it doesn't make sense.

Top is OEM setup, it seals by the threads and screwing the hose all the way to the flat surface. I'm now seeing they didn't originally use a crush washer.

Bottom is a new tee with flared seat and since the hose has a compatible end it should work. But this appears uncommon to other tees I see that have a male end where the hose goes, and it's usually a hard line that has a male fitting. So there might be a reason this isn't used often.

Is either fine or one better than the other?

What vehicle?

Neither of those hoses use the thread as the sealing surface. They both use the inverted flare at the end of the threaded fitting as the sealing surface.

you are correct that neither of those hoses would use a crush washer.

The flare in the bottom block is an SAE flare and is requires the mating SAE inverted flare to seal properly. I don't think the hose shown has an SAE flare. The angles and diameters are different, and will likely leak if used together.

This is for a first generation (1981-1985) RX-7.

The seat on the OEM tee is actually concave and the hose threads all the way until it stops at the exterior. It had been working on the car that way, but still bugs me.

The rx7 shouldn't bottom the head against the block.  They have super long ends that should seal against the face at the bottom of the hole.  They did change various things from year to year on the 1st gens.  It's possible you have 2 different years of fittings there.

To be clear, I don't think either of those is correct.

AngryCorvair (Forum Supporter) said:

What vehicle?

Neither of those hoses use the thread as the sealing surface. They both use the inverted flare at the end of the threaded fitting as the sealing surface.

you are correct that neither of those hoses would use a crush washer.

The flare in the bottom block is an SAE flare and is requires the mating SAE inverted flare to seal properly. I don't think the hose shown has an SAE flare. The angles and diameters are different, and will likely leak if used together.

 

Quoted cause I didn't read who actually made these statements...

Angry is a brake engineer.  Listen to him!

wvumtnbkr said:

To be clear, I don't think either of those is correct.

The old one is definitely OEM. Surprisingly difficult to find photos from the correct angle but here are a couple of examples:

RockAuto may have sent the wrong hose, but I've used the same kind before, and what other fitting would it take? The end of the tee is concave and there's 16mm of thread.

Some of the Japanese stuff uses "JIC" flare which IIRC is 37 degrees, looks a lot like SAE which is 45 degrees. I'm not specifically familiar with RX7 stuff. An RX7-specific forum might know. 

Mazda never used bubble flares on anything, always double flare.

When they threaded a hose into something, they always used a crush washer to seal the connection, not a flare machined into the female threads.  The first image is correct, threaded into the junction with a copper washer to seal it.  The flex hose appears to have been made wrong, as it does not locate the crush washer.

The front (and rear, if present) calipers and the clutch slave cylinder are the same way.

The parts diagrams didn't help by sporadically showing the crush washers. They show them going into the front calipers but not the rear calipers or the rear axle tee.