The arm cylinder drifts down when extended, does cat have a saftewy suction valve on there valve bank? And is the compensators in the same place as a komatsu?:Banghead
do you mean the stick drifts in towards the machine when extended outward? im not sure of any valves you are talking about... theres possibly a drift reduction valve, does it drift one way or both?... try bringing the stick all the way in and curling it under the boom, see if it drifts the opposite way.... or dig the teeth of the buck into the ground, then try walking back or forth, watch the stick cyl for movement. whats your serial #?