Cub Cadet hydrostatic tractors use hydraulic pressure to power the transmission and attachments that connect to the hydraulic system. Low hydrostatic fluid levels decrease the pressure in the system. This causes the system to function at a decreased capacity or in extreme cases to stop functioning. Maintaining the correct fluid level ensures the tractor operates as designed.
Flip the tractor seat toward the steering wheel.
Remove the two frame bracket screws holding one frame bracket to the seat by turning them counterclockwise with a Phillips screwdriver. Slide the seat from the tractor and set aside.
Match a socket to the size of the bolts connecting the frame cover to the tractor. Connect the matched socket to a ratchet handle. Turn the two mounting screws counterclockwise to loosen the frame cover. Pull the screws from the cover. Set the cover aside.
Turn the vent bolt located in front of the clear expansion tank counterclockwise with an adjustable wrench. Remove the bolt from the transmission.
Pour hydraulic fluid into the vent hole. Stop pouring when the fluid level reaches the "Full" line.
Tighten the vent bolt into the threaded hole with the adjustable wrench.
Reattach the frame cover to the tractor. Slide the seat onto the seat bracket.