Does anyone know the thread pitch of the brake line fittings that fit into the master cylinder on S4 TII models? I am assuming they are metric...

Thanks

 

10mm x 1.00

 

Haha... thanks clokker... I was initially going to direct the question at you in the first place I figured you would know the size from your master cylinder switch out!

Thanks again!

 

10mm x 1.00, inverted flare is pretty much the standard size for all Japanese brake fittings, which makes it easy to interchange master cylinders, calipers, etc.
Many European cars use that size as well but the flare is different (bubble flare instead of inverted) and not compatible.

I wish they'd have adopted a coarser thread, it's very easy to crossthread the 1.00 pitch fittings, especially when under tension from the hard line and it's common to see screwed up/rounded fittings in the junkyard.
For that reason you should always start the fittings by hand- properly engaged, you can screw them almost all the way in before needing a wrench (flare nut wrench, please).

If you encounter resistence, STOP!.
The steel brake line nut will chew up the alloy of the master cylinder/caliper in a heartbeat and you'll be SOL.

Another thing to watch out for is the coating on the brake hard line.
Many OEM hardlines are coated with a green type of finish (I don't know if it's a paint or a chemical deposition coating) that gets soft and flakes under the threaded fitting.
If a bit of this coating gets inside the hardline flare, you'll have a hell of a time getting a good seal ( for "hell of a time" read: NEVER), no matter how hard you crank on the fitting.

There...that's what I know about brake line fittings.

 

Cool beans. So the inverted flare is the same degree as domestic vehicles, I am assuming? I bought a line lock, which uses 1/8" NPT fittings, and a double flare tool. I need to make some line adapters.

 

I know nuttin about domestic specs but I'd be hesitant to assume anything.

Yeah, that was helpful, wasn't it?

 

No problem. I appreciate the info you have given me already. I guess I will dive into it, and figure out the rest as I go!

Thanks again!

 

Aha! I see what they are doing. They manufacture them with 1/8 npt fittings, so all you have to do is buy adapters (i.e. 1/8 npt by 10 x 1). Screw your 1/8 npt adapter in, which seals by itself, and then screw your brake fitting into the adapter. Makes sense!