When I boom down, the boom is real jerky. All of the other functions are smooth operating. Any Ideas ?.
Cavitation, air? Low hydraulic oil level? Bent cylinder rod? Pins not greased adequately? My first guess would be a bent boom cylinder rod. Put boom down solidly, knock out pin where rod connects to boom and pull cylinder away, chock up and extend rod all the way out, put a straight edge on it or just observe, should move in and out freely without arcing or appearing to bend when coming in and out. Bent rod is a common problem on these machines. Good luck. :drinkup