REAR CYLINDER

550 373 97 CYLINDER is one of those workhorse hydraulic cylinders that provides the brute force for moving or positioning a major assembly on your rig, often something like the feed beam or a boom section. It’s what actually pushes or pulls a heavy load, translating hydraulic pressure into linear motion. Think of it as the muscle that gets the job done, whether that's extending a boom out to reach a new spot or pushing the drill head into position. Without it, things just don't move right, or they don't move at all.

When this cylinder starts to wear out, you'll usually notice a few things. The most common sign is drift – the assembly it's supposed to hold steady will slowly creep out of position, even when the controls are neutral. Or, you might find the movement itself feels sluggish, like it's fighting you, taking longer to extend or retract than it should. Sometimes, you'll even hear a bit of internal noise, a kind of groaning or chattering, especially if the seals are really gone and fluid is bypassing the piston. External leaks around the rod seal are obvious, of course, but that internal bypass is the real sneaky one that causes drift.

Replacing one of these isn't rocket science, but you definitely want to do it right. Always check the mounting pins and bushings for wear when you've got the old cylinder out; they often get overlooked and can cause premature failure of the new one if they're sloppy. Make sure your hydraulic lines are clean before hooking up the new cylinder, and for goodness sake, bleed the system properly after installation. You don't want air trapped in there causing spongy operation or worse, cavitation damage down the line.