Acetone and transmission fluid mix at 50/50 has been a preferred loosening agent in stuck antique Cat motors for years. Remember though, not all engines come loose. You have nothing to lose by trying though. Some have also used a porta power pump to push heavier oil into a piston that is up to get things moving. Just make a adapter for the injector port. You may have to remove the rockers to insure the valves are shut. May be a little drastic but again if you need to tear down otherwise it might be worth a shot.
Yes, I have a service manualDoes anyone have a service manual for it?
I had a 1952 Northwest Dragline that was stuck last year. It had a Cat 8800D with a pony motor. It had been stuck
Reminds me of a story an old operator told me of having someone push a junk old crawler crane to death row. The plan was for the loader to get it rolling (it was a small down hill grade) and he was going to stop it with the master clutch. The 3-71 was locked up from water down the exhaust, he said when he threw the clutch in, the old jimmy broke free and went full song taking him through the fence, down a hill into a creek/ditch.
They finally got it back up the hill and used it on a couple more jobs after the fuel rack was freed up.
This was a true Wild West get r done outfit not far from me.
Can I just put this thing in neutral and push it on a trailer?