Brake and clutch fittings and spanner sizes? What's needed?

Hello

I need to do a bit of work on my van’s hydraulic system (brakes and clutch). I know it’s recommended to use flare nut spanners on the fitting but I don’t have any so I think I’ll get a set.

I had a quick look around the van and the smallest I could find was a 10 mm. This seems to be a really common size and is used in lots of places. There are a couple of fittings that need a 12 mm. The biggest brake fitting seems to be a 17mm on the rear flex hose; I will probably be replacing this hose so it’s possible the replacement might have a different spanner size.

So, question 1, can anyone say if there are any hydraulic fittings smaller than 10 mm or bigger than 17 mm?

I’ve found some bigger A/C fitting but don’t intend to disturb these and I think there’s little need to use a flare nut spanner on these (22 mm and 27 mm for example).

Question 2 (several). What is the thread type for the hydraulic fittings? I’m presuming the whole vehicle is metric but is this correct? Are there any non-metric fittings? In M10 and M12 I think there are three thread pitches (1.0, 1.25 and 1.5). Does anyone know what was used?

Question 3. If everything is metric what type of pipe flare is used? I’ve come across ISO (bubble), double flare and DIN (mushroom) but no idea what Toyota used in their domestic market vehicles.

Hope this makes sense and grateful for any assistance.

Cheers!