cat 302.5 boom cylinder problem

I have a 2000 cat mini excavator serial #4az01091 302.5 the main boom cylinder is falling several inches when I pull back on the stick also if boom is in up position and I want to raise it more barely pull back on stick boom will ease all the way down does the same in the down position of the stick any one have any ideas THANKS

cat 302.5 boom cylinder problem