Thanks for links. Exploded diagrams are very useful too. I have taken the rear "suction filter off" and found some debris in it (guaze or similar), not much. Looking inside it it looks quite dirty. No idea when it was last changed. Oil looks clean enough following draining. I am wondering if filter is chocked and starving pump of hyd fluid/oil? Tempted to reasemble so full filter and oil change and see if it works?? What are peoples thoughts - worth a go? If it doesn't work I trust i can collect new oil and reuse again therefore nothing to loose but a couple of hours labour? One thing i am keen to learn is that is there an alignment setting for the shaft exposed? Looking through i can see a series/sequence of holes....does this need to bet set before refitting casing? Many thanks, Dave
i have been in similar situations and put back together. "usually a mistake" i also notice the oil in the picture of the tub with you holding something above it. is that the oil that came out of the HST??? looks real bad to me. i would just rebuild it while i had it torn down but i would not proceed until i had some sort of workshop manual. yes the plates have a right and wrong way to be installed as they are what regulates the volume of oil entering the high pressure pump.
also you should get a filter cutter and take the filters apart and look for debris in the media. don't use a hacksaw get a proper cutter. anyone who has a hydrostat should have a filter cutter and inspect at every oil change,it can save you allot of trouble