My cub cadet rzt 50 does nothing when i pull the pto knob

SOURCE: I have a Cub Cadet RZT 50 mower. The left drive

First, check the level of the hydraulic fluid (usually the dipstick is right inside the fill cap, and you just raise the seat to access it). If it's low, fill 'er up with the right fluid.

If that's OK, test if the lack of 'pull' affects the left wheel in both forward and reverse -- try going up a hill forward, and backing up it in reverse. If it affects both directions, maybe you will be lucky -- the problem could be that the bypass for the left hydraulic motor has opened somehow. (The bypass is used to let you push the mower by hand in case of an engine failure, etc.) So look for a fat-headed bolt sticking out of the left hydraulic motor. Check that it's tight -- rotate it just like you would tighten a bolt, clockwise. If it wasn't tight, that may be the problem; just tighten it and try the mower.

If this doesn't resolve it, you probably have a problem in the hydraulic valves, hoses, or motor, and a trip to the dealer is needed. Probably won't be cheap, sorry my friend. Good luck, and please rate if this was helpful, thanks!