Rob, the work is done in the pit and on the machine but I do believe you may have misinterpreted what Gav wrote. You do not have to remove the cylinder as a whole nor the head or rod. On Komatsu's excavator cylinders you have what they call a flange bushing which is bolted to the cylinder head. When the cylinder leaks (from the chevron seals), as Gav said, you can remove a shim of 0.8mm thickness (2 halfs) for re-packing (sealing). Each cylinder has four (8 halfs) 0.8mm shims and 1 (2 halfs) 2.0mm shim. Once you have removed all the shims it is time to repack the flange bushing. To do this, you simply remove the inner circle of bolts on the cylinder head and slide it up the rod, remove the sealing elements and replace with new (which comrpise of hard-plastic backring, back-up ring, 5 chevrons and a header ring) In the top of the support bush is a scraper ring retainer, seperate this to remove and replace the scraper ring (wiper seal) Put it all back together, with new shims and torque the bolts (Dont know the tension of the top of my head sorry
) Start the machine and hope the oil leak has stopped! Sorry I dont know the barrel diameter, I would take a guess but I'm too pedantic, I would preffer to give you the exact measurments, but I will find out. Hope this answers some of your questions
