hydraulic system emptying itself into the lower gear case, can't find source
There is a little hydraulic swivel in the middle of the machine. It carries speedomatic oil down the vertical shaft to operate the travel dog clutches. It’s under a cover under a horizontal shaft. You usually have to pull that shaft to get access to it.
There's also two hydraulic hoses in the bevel gear case. You'll have to drop the big bottom pan to check it though.I'd repack the swivel first and see if that's the issue before you go to the trouble of pulling that bottom plate. There's a drain plug in the plate that takes a 1/2 inch drive ratchet. It can be full of mud and hard to find. crank the mach ine and build accumulator pressure and shut it off. Engage the travel on one track and observe pressure drop. start engine ,bring pressure up and repeat on other track. If a hose is blown one side will lose pressure quicker.
The last crawler crane job I did was a snapped off lower vertical traction shaft in a LS 108B. what a royal pain-everything siezed up,rusted up and pure misery. The groove for the huge snap ring that holds the bottom bearing was crushed shut tightly around the snap ring making it a press fit of sorts. Then found upper shaft and coupling worn completely out and had to replace them as well. Job got bigger and bigger. Never again.And all because the idiot running it thought it was a good idea to rev it up all the way and slam it into travel,