No power on slopes with my zero turn 54" Husqvarna

[Cytubb]

The right hydro gear has no power on slopes. I put a new belt on it . There is no visible filter or way to check the fluid. Any help would be appreciated .

 

[Carscw]

When on flat ground both levers forward. Does it go to the right? Or go straight?

 

[bertsmobile1]

Model number of mower and a photo would be good.
Serial number from the engine would be even better.
You know what mower you have .
We don't
So we can not help you