We have an 2010 8120 combine that keeps blowing an O ring on a solenoid valve within the big brass valve block on the left side of the feederhouse. I've replaced it maybe 4-5 times and each O ring will last about 50 hours before it blows again. I know its a certain metric size and its not a terribly hard fix but does anyone have any ideas what would be causing this to happen? Its on the solenoid that controls the reel fore+aft on the bottom of the block. The sensor has a little torque sticker saying 4-6 ft lbs.