Vermeer 504 M Classic troubleshooting

I am hoping someone can lead me in the right direction on this problem.

 

I am not getting any pressure reading on the bale density gauge on the baler.  Just coming out of winter storage - tailgate lifts and it started a first bale quickly but sounded like it was binding at around 35 inches.  We noticed that there was no pressure at the gauge - loosened the line at the gauge and no oil. Took pressure off the belts and checked rollers and all seems well inside.

 

The only item in question - is the density adjustment valve.  It was loose and when we try to run it back in it does bottom out at what should be full on.  Does all of the hydraulic fluid come from the tractor's system? Does it need to be purges or bled down?  The manual shows a problem with an over fill of hydraulic fluid which shows pressure on gauge with tailgate closed.  How does it get over filled?

 

Many thanks for any help - have hay on the ground and baling with larger machines - but need some 4x5's for a special order.....

 

Greg

Vermeer 504 M Classic troubleshooting