Complex sentence: Due to new inspection troubles the S-Bahn network was again reduced dramatically on 8 September 2009 when 75% of the trains were withdrawn from service due to inspection and faulty brake cylinders.
Split into simpler sentences: Due to new inspection troubles the S-Bahn network was again reduced dramatically on September 8,2009. As of that date, three quarters of the trains were withdrawn from the network due to inspection and faulty brake cylinders.