Pisten Bully makes a pressure test kit with everything you need for around $600 the last time I checked. It sounds expensive but the ski club in Anchorage made their own test equipment and figure they had a little more than that into piecing it together at the local hydraulic store. The correct fluid filled gages are kind of spendy and I think there are 3 of them.
I suggest you call Pisten Bully tech services and they will help you out with any problems and it's free. They are great to work with and always friendly. I was going to buy the kit last year for my 260D but never cracked the wallet.
There are a total of 5 pumps to check, 2 for the drive, 1 for the tiller, 1 for the aux hydraulics and 1 charge pump. The main pumps are best checked under load, at operating temps while the machine is moving according to the tech guys.