Confused about wheel motor closed loop circuit

[oldnslo]

Yes, it has a suction side filter...but it's only 10 micron and filters the make up oil in the closed loop.

To that point however, this tractor does have case drains on all wheel motors. So, it's possible the closed loop does get new oil over time.

This wouldn't be true for my 425 though.

Regarding the filter, I built a filter using check valves that's reversible.

A good 10 micron filter will keep the closed loop system from getting external contaminates.

Did you build it so that your filter works in both directions or filter in one direction and free flow in the other? One direction is how the HST filters I have seen work. Filtering in the forward or most common use direction.