Spent 9 hours chasing a hydraulic leak on a Liebherr 81K that turned out to be a $12 o-ring
Last Tuesday I noticed a small puddle of hydraulic fluid under the slew motor on the 81K we keep at the yard in Denton and figured it would be a quick fix before the morning lift. I pressure washed the whole area, ran it for 20 minutes, checked every fitting with a paper towel, and still could not spot where it was coming from. Ended up pulling the motor cover off, draining about 4 gallons into a bucket, and tracing the whole return line with a flashlight before I finally found a pinched o-ring on the pilot line that was seeping only under load. Nine hours of my Wednesday gone for a part that cost less than my lunch. Has anyone else had a leak that only shows up when the machine is working, and what is your go to trick for finding it faster?
Ever try the old cardboard trick under the machine overnight? I used to laugh at guys who did that, thought it was a waste of time when you could just crawl under there with a light. Then I watched a guy find a seep in ten minutes that I'd been chasing for a whole shift. He slid a clean piece of cardboard under the motor, let it sit under load for a bit, and the drip pattern pointed him right at the fitting. Now I keep a stack of flattened boxes in the truck and it saves me hours. That pinched o-ring deal sounds brutal though, those load-only leaks are the worst to track down.