I've had a couple of the flat face o ring hydraulic fittings fail on my skid steer. The first time it was something easy to get to under the cab. This time is was one of the hoses connecting the 2 speed gear box behind the sprocket. I had to pull the track and fight like crazy to replace this one. How do these fail, assuming the fitting is tight there is no movement between the two pieces. It just baffles me, mainly I'm venting because this last one was a huge PITA to repair. I can't imagine taking that to a shop, 600-800 bucks in labor for a dollar O ring?