Caliper thread size?

[Treppid]

Hi Folks. Just refurbishing a pair of 'S' type (X200) rear calipers, the big single pot type. I can't for the life of me figure out the size/thread for the banjo bolts on the brake pipes. It looks a very coarse thread and my metric test bolts just bind straight away, are they some kind of imperial size? Any advice much appreciated!

Neil ('S' type trike)

[Treppid]

Just a thought, when fitted to a car, are there actually flexi hoses fitted into the calipers? It could be that with my trike, I've got rigid brake lines with a banjo bolt instead? Does that help at all with identifying the thread size/pitch?

Cheers... 

[Treppid]

Further investigation reveals I DO have the flexi hoses feeding to the calipers! The caliper end terminates in the square fitting through which the banjo bolt goes into the caliper. It's this bolt I'm having trouble sizing, anyone got any suggestions please?

Cheers....