Gordon,
Hi there...as a relatively NEWBIE too....maybe this helps ?
I found a place in Aldershot - Mercury Prestige Vehicle Service, they specialise in BMW & MBenz. Been going just over 4 years.
Took my 530 touring along 2 investigate fluid leak (passenger footwell) Richard (BMW guru) in about 10 mins discovered it was brake/hydraulic fluid. Took out glove box + centre trim panel, it was a leak from the brake booster assy. I understand its similar to a servo...but ask no more - recovering from shock at the cost to fix !!!
Booster is 537 (brand new)+ labour to fit, 2 hours @ 25ph..not much change from 600
Otherwise well impressed with speed & level of knowledge, but dont take my word...try 'em out ?
Their Address: Beechnut Ind. Estate, Beechnut Road. Aldershot GU12 4JG. 01252 318318 speak to Richard.
All the best...Tony