Good chance for a simple problem here; you probably have a bad seal or broken piston on the B1 band. It can be removed from the outside and MB has redesigned the piston so a complete assy should be installed (it has a much broader teflon seal). I will try to post a part number tomorrow.

------------------
Steve Brotherton
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician