Terex PT110 hydraulic tank venting/equalizing

[terrydodge]

Hi folks,
I recently bought a 2013 pt110 and am confused by it not equalizing between the three high points in the hydraulic system. That is, the two high sides of the U shaped tank and the filler tube. There always seems to be trapped air showing inaccurate readings on the gauge. It has vent lines between these points that seem to be passing air fairly freely.

Any experience with this out there?

Thanks