650 gs brake light switch

[hovis]

Could anyone tell me the dia and thread pitch of the banjo bolt on the m/cyl. My front brake light switch has failed in the on position and bmw want £22 for a new one, not going to pay that for a micro switch especially when I may be able to get a hydraulic one on E-Bay delivered for £9.99, or if I need one anyway for m.o.t etc
Thanks Hovis