L553 no Hyd after oil change

[Mattd]

Just got my first skid steer. It’s older but only has 2100hrs. Everything seemed to run well and function properly. I just got done going thru and replacing all liquids and filters (except hyd oil filters, manual says to run it for an hour after oil change, then Change filters). Now boom won’t go up. It goes forward and reverse without a problem, so I moved around a little (I left the back open, and now can’t close it w boom down). The tilt started moving a little by, like an inch. The motor sound changes a bit when I move a peddle, but was too timid to stay on one for long. There would appear to be what looks like a bleeder screw right at the top of the pump. I small square headed bolt. Haven’t opened it yet. Any ideas?

 

[Tazza]

Did you sort it out?
I wonder if ithere is just too much air in the system, but never thought it would be an issue.
Could you have stuck the aux hydraulics on?
Hopefully Moke10 will pop his nose in and give some advise, i bet he has changed thousands of filters on NH machines without issues.