Question about valve body

[Bigbear4x4]

Hello people ! I have a 2004 John Deere 4115 with 840 hours. Absolutely No leaks on my garage floor.
The fel will not stay up when I turn off the tractor. Over time it creaps down till its completely down. Frustrating , I'm thinking the valve body is the problem. If I am right, do I replace the valve body or is there a rebuild kit available.?
During the winter I have a rear snowblower and I can raise it in the evening and it hasn't dropped overnight. 2 different independent systems I imagine.
Tractor is always parked in my heated , 55° , garage. In northern Maine. Any thoughts would be appreciated. Thanks

 

[old and tired]

It could be a leak within the cylinders and they might need to be repacked. Leak from pressure side to the other side, you would not see external oil. Or, it could be both the cylinder and the valve body!!!

 

[Bigbear4x4]

Ok, thank you for your time. Gonna get some help and check these out