I resently purchased a 1998 B21. I’m having an issue with the PTO lowering my blade. It will lift the blade but very slow to drop. It worked several times but I’ve only run the tractor about 3 hours. The fluid level is ok and the lever to ingage the PTO is up. It has been used when it was cold but warmed it up 15 plus minutes before moving. Any suggestions on my problem would be helpful.