Not that I'm aware of . I assume one would just cycle the steering lock to lock with the wheels raised to purge any air , then recheck the fluid level in the tank .
I've changed hydraulic filters with no problems as far as bleeding .
I had a new PTO shaft built for my Ransomes 728 mower and the components are manufactured by Weasler . The u-joint
used is Part # 200-0600 which is a "6" series u-joint . They are available from any power train supplier .