3-Point Hitch 1500D 3 point hitch control valve?

[Suds]

I recently changed the hydraulic fluid and cleaned the filter on my 1500D. I used it one time since then for a couple of hours to till the garden and everything worked fine. Today I used in for half an hour and when I put it away, the 3 point hitch wouldn't go down. Appears the pin on the back of the hydraulic control valve free floats.

Entire assembly is available from a dealer but quite expensive. Wondering if there is any other alternative, i.e. dismantle and clean?

OTS, I had the same condition on my 1610D, as I also had a 1500 with the same
3pt valve I decided to try a switch. After I removed the valve from each of them I realized that the spool in the 1610 valve was stuck in the valve body. I carefully beat it out using a piece of dowel as a punch. I polished the spool with emery and lubed with wd 40 it would then move freely in the valve. I reassembled it and have had no trouble with it since.

 

[Onthesauk]

Thanks Suds, that may be my first try.

My tractor expert down the street suggested maybe an air bubble. I used the tractor hard for a couple hours after changing the fluid so hard to imagine that any air wouldn't have worked it's way out. Anyone experienced this?

 

[Onthesauk]

Got a replacement hydraulic control valve from Hoye yesterday, installed today, took about an hour and everything works fine again.

Thanks for everyone's help!