Bought tractor used; 285 hours. Initially would raise hitch when position lever was half way up or more. Progressively over last 5 hours of use has gotten to where it won't raise until the lever is all the way up/back, and even then it takes a second to start raising. Still lowers fine, holds its position, and it is not related to the knob below the seat governing the lowering speed. Front loader bucket hydraulics work fine. Is there a hydraulic fluid valve specific for the 3 point hitch that could be clogged or not opening like it should? If so - is it user-servicable by someone with fairly decent automotive (but not hydraulics) knowledge? Thanks!