I just had some work done on my bucket cylinder and had it off for a couple days now I reinstalled it and an old hose blew so I replaced this then filled hyd fluid and now, boom will raise but not lower. Unless engine is shut off and you feather the pedal. Also the bucket cylinder is totaly inactive. Could this be an air lock problem? valve body problem? Filter? Machine was working fine but had to have a part welded on the cylinder.