..Down Leveling Pilot Failure..on last place to look if the I/o board changout doesn,t work...Have had random problems in the past on the UC4M Maxton valve..actually had to take the down section apart and found the piston bore was pretty scored up from many runs..emory and clean completely..added CatOIL to the assembly reassembled this problem never surfaced again..when all else fails...good luck...
