Recently I had the seals of my Zaxis 200LC excavator changed. When the cylinder was reinstalled and correctly reconnected to the hydraulic lines I observed that for the first few minutes everything worked well. However after that the arm cylinder slows down. If the engine is placed on idel for a couple of minutes it works good again, but just for 2 - 3 times. I have replaced the cylinder and it same thing happends. What do you think is causing this? Please nofe that the hydraulic oil filled prior to reinstalling the cylinder is not the OEM recommended hydraulic oil. Do you think this could be part of the problem?