Mystery brake problems

Oh dear, just before Christmas I had the R1150RT serviced, and as I drove away from the BMW main dealership, the brake warning light started flashing. Back to the dealer who put it on the diagnostics and could find no problem. This happened twice, advice was to fit a new battery, which I did and all seemed well. 

Fast forward to two days ago, first ride after the service. Into the Peak District only to find the brake warning light flashing after about 10 miles. Minor panic, but brakes appear to be working, so I stopped at the top of Holme Moss. On restarting the light was fine, so I continued, but the same thing happened twice more.

I am now sitting in the dealership looking enviously at new shiny metal. While my veteran is being probed and prodded to see what might be causing the light to flash. With the battery theory demolished we are now lookin at a filter on the servo pump and re bleeding the brakes. Fingers, and other things crossed.

Apparently the servo system is notoriously shaky on these bikes. Internet research has raised the possibility of removing the servo altogether and riding with a traditional braking system. If the worst happens this would be a better solution than £1500 for a new servo!