according to BMW it is/was every 30,000 milesWhats BMW's recommendation? I could'nt find anything in the manual. At 70k and dark brown in color I think Im due.
Also any idea on cost a dealer? 1hr + parts?
That is a good idea...Should be red, not brown. I did mine at 55k miles and it looked like coffee...I had the pump replaced probably 2-3yrs before so fluid was pretty fugly in that time period. I never did find any recommendation, but I plan on <2yr intervals going forward.
You may also want to have them take the resevoir off and back flush it since the internal filter cannot be replaced or just replace the resevoir since it comes w/ new filter and cap.