hi all sometimes when my machine is cold and i track some distance to my workplace it seems there is an airlock in the boom and dipper and it take a couple of full extensions of the rams to clear, this only happens in the first hour of operation. hyd level is good anyone had the same problems or know why it would happen.
i have been operating a couple of liebherr 954 and they had the same problem and the only thing we could figure out was that it had to be cold/thick hydraulic oil as soon as the oil was warm there was no problem
the 345B'S i've ran have done this a red light showing the hyd.would come on you would have to walk it a ways and let off the track peddles or as you say exercise it a bit then it would be fine the 345's are the only cat hoes i have had this happen.
Our first forestry harverster was an old PC200 with a slingshot head on it. When you started it in the mornings it would be very laggy (same thing you are describing) and the hydraulic light would come/stay on until the oil had warmed up. When you are doing full extentions its getting the oil moving which in turn warms it up. Try holding the bucket curl open and letting it dump over relief for a while until the hydraulic temp comes up. Then move your boom and stick. I'm willing to be the problem goes away alot quicker (you may still notice it minorly as there would still be cold oil in the cylinders).
thing is , if you only track a short distance it does not do it... only when tracking a couple of hundred metres or more . does not bother me as i know about it and informed the our fitter a year ago , i had a week off and another driver was on it and he was moaning about it.
i am sure its because of cold/thick oil so when you track a distance the trackmotors will use almost all the oil the pump can give and when the oil is cold it will be feeling like there is air in the system dont know if im wrong but its the best bid i have:beatsme:beatsme have a nice day
There may be load locks in those circuits and the cold oil is making the issue worse. Basically a load lock keeps the cylinder from collapsing in if a hose fails. It also locks the cylinder from drifting down when a load is on it. It is just another valve that is closed when there is no oil going to the boom or stick. In order to open it you have to put down pressure to the circuit. There is a connection to the down circuit that opens the load lock valve and lets the cylinder go in. Vantage has a good suggestion in holding the bucket over relief for awhile to warm the oil that is in the tubes. Good Luck!