In my free email series, on YouTube and in exhaustive detail in The Hydraulic Troubleshooting Handbook, I explain the concept of how a double-acting cylinder becomes a displacement cylinder if the piston seal leaks. And as part of the explanation of this concept I state: “…if the piston seal is completely removed from a double-acting cylinder, and its ports … Read more

A hydraulic machine has lots of moving parts to maintain. In fact, a hydraulic system is one of the most complex systems to maintain effectively. And here’s one more item to add to the list: the machine’s drawings. A machine’s hydraulic (and electrical) schematic diagrams don’t wear out, but they do tend to become inaccurate over time.

Even absent a … Read more

Air is both a normal ingredient, and a contaminant, of hydraulic oil. It’s a normal ingredient because hydraulic fluid typically contains between 6 and 12 percent by volume of dissolved air. There’s no avoiding this. And provided this dissolved air stays dissolved, it poses no problem to the hydraulic system or the fluid.

But if this dissolved air comes out … Read more