Bleeding air from closed loop hydraulic system the right way

If you're currently struggling with bleeding air from closed loop hydraulic system components, you already know how frustrating that "spongy" feeling can be when you move a joystick or hit a pedal. It's one of those maintenance tasks that sounds simple on paper but can turn into a real headache if the air just refuses to budge. Unlike open systems where air eventually finds its way back to a large reservoir and bubbles out, a closed loop (like a hydrostatic drive) is much more stubborn. If that air stays trapped, you're looking at more than just sluggish performance; you're looking at potential pump damage from cavitation. ...

February 20, 2026 · 7 min · Tranent Coehn