Warning: That little oil leak on a Cessna 172 at KAPA cost me a whole Saturday

I was doing a pre-buy on a 172 at Centennial Airport last month and saw a tiny seep from the crankcase seal. Figured it was no big deal, just a wipe-down and send it. Well, three hours later I had the cowling off for the fourth time chasing drips that kept showing up on the belly. Turns out the seal was barely seated from a previous overhaul and it was pulling air under load. Ended up having to pull the prop and the alternator to reset it right. Has anyone else had a small oil leak turn into a full day project on a little GA bird?

2 comments

2 Comments

emerychen6d ago

Man I used to be the guy who would just wipe a little oil off and call it good. But after I chased a similar seep on a Cherokee 140 for two full days last year, my whole mindset shifted. Ended up being a tiny crack in the accessory case that only showed under oil pressure, and I had to pull the whole front end off to weld it. Now when I see any amount of oil that isn't just a normal drip, I plan on it taking the whole day because it always does. Those little leaks are never just the leak itself, they're a symptom of something else that got messed up during the last repair. Sounds like your crankcase seal was just the tip of the iceberg.

tylerr395d ago

Man that's exactly how these things always go. It's like that old saying about how if you give a mouse a cookie, except with airplanes it's "if you wipe a little oil leak you're going to end up pulling the alternator." I've noticed this pattern in so many other things too. Like when my buddy tried to just replace a single cracked tile in his kitchen floor and three weekends later he had the whole subfloor torn out because of water damage hiding underneath. Or how I tried to fix a loose cabinet drawer once and ended up rebuilding half the kitchen because everything was connected to everything else in some stupid way. It's like the universe decided that small problems are never allowed to stay small, they always have to be the tip of whatever iceberg is sitting underneath waiting to ruin your whole day. You think you're just wiping a drip but really you're signing up for a full day of disassembly that you didn't plan on.