Whilst on track on Saturday, the "brake light on" warning light popped up. Obviously I slowed down immediately, pulled off and checked out everything.

So, wheels off, check pads (no electronic wear indicators) and checked fluid level. Pads all had loads left, fluid was new, synthetic non-boilable stuff and of sufficient level.

Hand-brake was off and *seems* to work OK.

So what was it or likely to have been?

 

sticking float switch in the brake fluid reservoir