PT 425 & john deere hydrostatic, DR Brushcutter 17 HP!!!!
Clumber
The Parker Corporation, which is one of the largest and most diversified hydraulic companies has a great teaching manual with great pictures in it, as does the Vickers Corporation another hydraulic giant.
There is no substitute for following all the hoses in your PT and getting an understanding of where they go and what they do.
Hydraulics is fascinating. Fluid power in general is one of the most versatile mediums available in power transmission and there is no subsitute for the amount of power that can be conveyed so efficiently into so many different mechanisms. Once hooked you'll start building all kinds of fun stuff