Brendan Casey's hydraulics blog

As you’re hopefully well aware, an unrestricted case-drain line is essential on a piston-type hydraulic motor, whether it’s axial, radial or bent-axis design. But when it comes to gear designs: external, internal and gerotor, a case-drain line is generally considered optional. This is because these types of motors don’t have a large-volume case or sump like piston motors do. ...

Noise reduction in hydraulic systems often involves isolating the pump and prime-mover assembly using flexible mounts (isolators). In these cases, the use of hose is necessary to maintain the isolation between the pump and prime-mover and the rest of the system.

The flip-side to this though is, although long lengths of hose can reduce structure borne noise, hose is act...

The objective of flushing a hydraulic system is to eliminate sludge, varnish, debris and contaminated or degraded fluid from conductor walls and other internal surfaces and system dead spots.

Reasons for performing a system flush include:

1. Fluid degradation – resulting in sludge, varnish or microbial deposits.
2. Major fai...