I haven't had too much of a chance to look into it and but just wanted to see if anyone ran across this before, Works great when cool but after about 15min she starts losing reverse power and then a few minutes later loses nearly all, however forward is still strong as hell. I bought the machine a couple years ago it's a spare and never really bothered me because we do a lot of large pads and don't use it much.... Now it's on a road job rolling in base rock and it's a problem.... It's an ex military unit only has about 1600hours. Pj
I know nothing about this machine, but with hydrostats in general a failure in one direction only will typically be a bad relief valve. Any chance it has Danfoss series 90 pumps? Multifunction valve. Could also be a charge check valve. Also look for towing valves, if it has them one might have worked loose, though usually these will affect both directions.
I'll check the pump for a tag tomorrow, I ordered a service manual for it but haven't got it yet. Thanks for the ideas Pj