m123 engine belts 1978/1979 m123 1978/1979 databook Mercedes states Belt A for alternator and waterpump 9.5×930 without clima9.5×960 with clima Belt B for powersteering 12.5×818 (as a replacement for earlier 12.5×825) Belt C for AC compressor 12.5×1285 Belt D for air-pump 9.5×825 M103 Without AC 2175
