Need some ideas? I replaced the cable on the pto that hasn't been used in a long time....years...The pto turns and runs fine, comes up to speed etc. but when I let go of the lever that you engage the pto then it just returns and won't stay engaged. Reading the shop manual it says that the hydrolic pressure holds the spool in place that engages the pto. I removed the spool and cleared the center drilled passage. The pressure reducing valve is free, and the modulating valve is free. I have not removed the whole valve body from the tractor and tried blowing out all of the passage ways in the valve body. Was hoping someone else has had this problem and what the fix was....maybe a new rebuild kit for the pto valve. All help is appreciated....thanks...