I work with hydraulic cylinder components every day, mainly honed tubes and chrome plated rods. Over the years I've become just as interested in failure analysis as manufacturing itself. I enjoy discussing materials, machining and real-world hydraulic problems, and I'm always keen to learn from people with hands-on experience."Every failure has a story. I'm just interested in figuring out what caused it."
It looks like the wiper seal is bad and allowed dirt / debris to get past it and damage the pressure seal in the guide. The materials used to make the seals don't seem to be as durable as they used to be. One thing to watch out for is ice on the rods in cold climates. Don't actuate the cylinders with ice on the rods, if the rod is going in the wiper seal will be damaged and if the rod is going out the ice can pull the seal out of the guide. Overheating will also shorten the life of the seals.
Good point. I've seen the same thing. Once dirt gets past a worn wiper seal, the pressure seal usually isn't far behind. Replacing the pressure seal without fixing the root cause often means the cylinder will be back on the bench sooner than expected.