2810 3 Point Hitch Issue

[d430kep]

My 3 point hitch operated normally the last time I used my tractor but when I recently went to use it it will not lift. I have a rear remote and it still works when engaged, so the pump is working.
I resealed the piston along with replacing all the other o-rings but didnt find any of them blown, just hard from age.
Any suggestions on possible causes?

 

[Destroked 450]

Did you dissemble and clean the control valve