MM55SR Parts Manual

This is in Japanese but gives lots of useful detail and about the parts

If you can't see this the Dropbox Link is below

https://www.dropbox.com/s/l4kkrmr2k12bmk2/mm55sr%20%20Full%20parts%20manual%20%281%29.pdf?dl=0

Page 1 Excavator main components

Page 96 Hydraulics

Page 220 Engine