Please, some help here. My 2006, Jinma 354 3 point hydraulic system stopped working. Working great one minute then would not lift rake. Pulled control unit off and clean but no help. Drained fluid and refilled with fresh fluid but no help. Drain fluid and pulled filter and filter was dirty but cloth on filter was torn so fluid was flowing. Also front end loader works great. After read a few different articles, I believe it could be the piston in the unit but don.t know how to check it.