My John Deere 445 has started to leak hydraulic fluid around the head of one of the bolts holding the hydraulic pump housing to the transaxle housing. It is the lowermost bolt that is leaking. I can't figure out what I should do to stop the leak. There is a washer on the bolt that I first thought was a crush washer but it looks like a lock washer. Is that washer really a crush washer that has broken or do I need to apply some kind of thread sealer at the threaded end of the bolt? The leak is very slow but I would like to stop it from leaking on my garage floor. Has anyone out there encountered this situation?