M10 fine thread.
You can re-use the old fittings if they are in good condition and not mullered with mole grips/hammer and chisel/temperatures equivalent to the suns core. You will need male fittings for where the pipe connects to the pipe union. Brake pipe (not the rubber hose) is 3/16" and you need to buy a packet of cupro-nickel brake pipe. It comes in 25ft rolls and should cost you about a tenner. Ask for 10mm male brake pipe unions - about 20p each.
Les.