As the topic suggests, does anyone know what size thread the hydraulic brake light switch that's suppied has?

If its the same as most, its an imperial 3/8ths.

[Edited on 11-5-13 by loggyboy]

If it is metric will most likely be m10x1 tapered thread

Thanks mates! I think my current switch is causing the spongy brake pedal and needs repacement. Or perhaps I should use an electical micro switch instead? Not sure yet..

Is your switched mounted with the outlet at the bottom? If so it is possible to get air trapped. Try removing the switch and fitting a bleed nipple instead and bleed to see if you he a solid pedal. I added an extra tee on mine to get the switch on its side, with a bleed nipple on top.

Yes, mine's mounted just like that. Thats the reason that I suspect the switch i causing my problems. I'll fit a bleed nipple and se what happens and take it from there. Thanks again!