How about a make and model of a "big wheeled excavator." The degree of possible damage to the system by the contamination depends on the type of hydraulic system in the machine. A wheel loader with gear or vane pumps will tolerate a lot more contamination with minimal damage than an excavator or other type of machine using variable displacement piston pumps. A machinery dealer would definitely say that an entire teardown, clean up and assembly would be the minimum requirement. I probably wouldn't touch the repairs on a machine in this condition without several pieces of paper that hold me harmless of any and all future problems with the machine.