RING, SEAL

560 313 78 RING, SEAL is usually found keeping hydraulic fluid where it belongs, often inside a cylinder or a valve body. It’s the little guy that stops oil from leaking past a piston or a rod, making sure you get full pressure and smooth movement. Without it, you’d just be pumping oil into the wrong place, or worse, all over the deck.

When this seal starts to go, you’ll definitely notice it. The most common sign is external leakage, obviously, but sometimes it’s internal. If it’s on a cylinder, you might see the drill feed or boom drift down slowly when it should be holding position. Or maybe a function just feels sluggish, like it’s not getting full power. You might also hear a slight hiss if it’s an air system seal, or just see oil weeping from a joint that used to be dry. It's usually a gradual thing, not a sudden catastrophic failure, so you get some warning.

When you’re replacing one of these, always make sure the bore or shaft surface is clean and free of nicks or scratches. Even a tiny burr will tear a new seal in no time. And don't forget to lubricate it well with clean hydraulic oil or grease before installation. A dry seal is a dead seal, especially during that first startup. Also, double-check the housing for any scoring; sometimes the old seal wears a groove that a new one just can't overcome.