Ok, put the tractor away last fall after pulling the square baler the last 40 hrs of operation. Went to get ready for spring cutting and the rockshafts will raise but will not lower on their own. Checked the control valve and hydraulics, everything seem ok. The rockshafts were all the way up, was afraid the cylinder was froze. Removed the seat and pulled the control valve (2 bolts). Rock shafts lowered. Cleaned the control valve and reinstalled. Same problem, they will raise but won't lower. Where do I start looking. 5303 with 112 hrs. Bought it 2 seasons ago and the dealer told me it is out of warranty. It has the Mita Harig pump assembly.