I have a 963 that started lifting slow and now it will not lift at all. When I removed the bucket the arms will raise but slow even at high rpm. I checked the lift cylinders and even repacked them to make sure there was no bypass. The linkage up to the control valve is working and you see the rod stroke valve. The fluid almost sounds like its dumping over a relief. The problem is I dont know enough about the control valve to determine if its something in the valve or low pressure from the pump. I also read a post where someone said the hyd pump is for lift and tilt the drive pump is separate for the drive system. Possibility of a bad pump? I need to put a gage to test pressure i guess. Any help or direction would be appreciated. Thanks