Hydraulic cylinder doesn't move

[Rusty red]

I was messing with my new to me 154 and tried to cycle the lift arms and the cylinder wont move. When moving the lever you can see the control valve move a little but that is it. Does anyone have any suggestions on why it doesn't move.
I did pull the level plug on the differential and it is over filled.

[MiCarl]

When you say "won't move" do you mean the cylinder won't extend or won't retract? I believe the cylinders on the Lo-Boy are one way - they only retract when there is the weight of an implement on them.

[Eugene]

When you say "won't move" do you mean the cylinder won't extend or won't retract? I believe the cylinders on the Lo-Boy are one way - they only retract when there is the weight of an implement on them.

Yes. One way.

You can retract the cylinder manually. Big lever on rock shaft and control valve open.

[Rusty red]

Ok that makes sense. Mine won't retract. I don't have a mower deck on.
I didn't know that it is a one way cylinder,I'm used to my fcub.
Thanks for the help.

[Gary Dotson]

I used to do service work on a lady’s 184. Each spring the mower would not go down. I would stand on the deck while holding the lever and the deck would drop, then work fine all season, do it again next year.