Rant: Spent 6 hours tracking down a hydraulic leak that ended up being a bad O-ring from the factory

I was working on a Gulfstream GIV nose gear retract cylinder last Tuesday. The system kept losing pressure and I figured it had to be a scored cylinder wall or a cracked fitting. I drained the fluid three times, pulled the whole assembly apart, and even borrowed a borescope from the lead mechanic to check for internal damage. Turns out it was a brand new O-ring that had a tiny, barely visible nick right where it sat in the groove. The parts guys swore the seal kit was good, but I replaced that ring with one from my own stash and the leak stopped immediately. I wasted most of a day because I trusted the factory part instead of checking the simplest thing first. Has anyone else run into a new seal that failed right out of the box?

2 comments

2 Comments

ben40219d ago

Stop trusting factory seals man, I've had two different Parker Hannifin O-rings fail straight out of the bag this year alone. Now I inspect every single seal under a bright light before it even touches a fitting.

margaret9919d ago

The Parker Hannifin thing got my attention because I used to swear by their stuff. I figured factory seals were just guaranteed good, you know? But after that GIV job where a brand new O-ring from a sealed kit caused a whole day of headache, I started checking every seal under a work light before installing. Now I keep a little magnifying loupe in my toolbox just for that.