We have a Deere 2520 tractor with mod mount mowing deck . Just bought a 200cX loader. We removed the loader to mow the lawn for the first time. We attached the hydraulics but we cannot lower the mowing deck to mow. Is there some sort of lock that is holding the mowing deck up to keep it from slipping when the loader is attached? Any help you can provide would be most appreciated. Can't find any help in the manuals.