Small Engines (Lawn Mowers, etc.): how to purge gearbox, cub cadet zero turn mower, cub cadet zero turn

Question
Hello Tim,
My husband has a Cub Cadet zero turn mower, zforce 50.  He changed the hydrostatic fluid and filter, now it does not move forward or backwards.  He says it's "air locked"  Can you give instructions on how to purge the gearbox please?
Thanks,
Laurie

Answer
Hello Laurie, sorry about the delay! First have your husband open the drainage plug. There should be two plugs; one for filling and the other to drain. Just crack the drainage plug so that there is enough fluid coming out of it.Secondly, open the filler plug and begin pouring the fluid, while the engine is running and then try to play with the levers that move the Cub forwards and backwards. Once the Cub is moving back and forth it's working and the air is gone! This is a two man job. Apply a little bit of judgement because mechanic work takes thought. Oh and buy some extra fluid and rags.