Hydraulic press loses holding force after ten minutes

What we told them

Holding force that decays with no external leak means the fluid is going somewhere internal — past a seal or back through a valve. Isolate by closing the line between the cylinder and the valve block while under load. If the cylinder holds, the valve is passing; if it still decays, the piston seal has failed. This one test saves stripping the wrong component, which is where most of the cost of this repair lives.