Occasionally when breaking, the brake fluid warning will sound and appear on the dash. this last until i stop braking. The fluid is full so isn't a problem, also the brakes operate unaffected. More annoying than anything else.

Could it be due to low brake pads??

Don't think so mate, the pads look fine and its the info display that beeps and displays brake fluid low.

Have you had a look at the wiring to the level sensor and checked the sensor itself?

Myrtle used to do this in the wet, once in a blue moon. I think it was probably damp getting into the ABS sensor, low pad sensor or something down that way. But it used to show up as Low Fluid Level. I don't know if they are connected?

Yep,
my '04 used to do this too - only in the wet though.

Nick