I have a B80PD that we just installed a replacement motor in and lo and behold the hydrostaic drive seems to have gone out. The drive worked well when the motor went out. We left is sitting for several years before finding an engine for it. I guess that wasn't a good idea.
Anybody have any suggestions on how to blow some lifr back into he hydrostatic trans? If not how big a deal is it rebuild one of these?
I would be grateful for any input here.
Thanks

The system is self bleeding. However if trapped in closed loup. simply drive against relief like a wall in both directions for a few seconds to pop open the R Valves.
Leaving set over night will allow the air to escape from the oil also.