International Harvester 3400A TLB Hydraulic Cylinder Question?

I am having trouble breaking down the cylinder on my IH 3400A I have tried a pipe wrench with a 10 foot piece of rigid conduit and all i seem to be able to do is bend the conduit. I am wondering if there is something that I am missing, that I have to do before I remove the cylinder retaining ring? any help would be great,
pics of the cylinder


thanks

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International Harvester 3400A TLB Hydraulic Cylinder Question?