JD 54D MMM drops while mowing

[TN Rambler]

I have a JD 2320 with a 54D MMM with independent lift and diverter valve option. The MMM is raised and lowered using the FEL joystick. When the deck is raised it will gradually drop back to the lower stop. Has anyone else had this problem? If so how do I correct it?

 

[J_J]

Either the cyl or the valve needs some work.

Most likely cyl seals.

Test the cyl for pressure holding and leakage.

If the FEL has load checks, inspect them for debris or damage.