does anyone know how to bleed a hydraulic system on a 1997 kobelco excuvator mark5 sk450lc
was it taken down completely dry? lines removed for cleaning? Most times the owners manuals will have specific instructions if needed, fill halfway, crank engine for four seconds, let sit for a minute, start and let run for x seconds, shut down and check level, fill 3/4 run for a minute and let sit for five. then fill all the way or something like that. Avoid running a pump dry ever, some pumps will have a case drain that can be uncorked to let the oil fill the pump before starting.
Just crack a fitting on the pump as you fill up the hydraulic tank. As I recall those run Kawasaki pumps so I think there were a couple of # 4 lines you could crack open. Once you have oil out them snug them up and start the motor at low idle. Give it a few minutes and then ease into a control a touch. When it starts to move do another. Work you way through and check the oil level as you keep doing this. When everything moves start running the functions back and forth a little more each time till you are all the way through their ranges. When everything is stroked out throttle the machine up and go to work. Good Luck
Agree with above with further comments - for piston pumps I loosen the servo control lines at the pump and leave loose until oil starts coming out. Bigger pumps have a plug on the case, so can easily bleed air out of there, or loosen the case drain line. For gear pumps I like to make sure they have no air up to the pump inlet. I have seen a small gear pump not pick up the oil before. For cylinders I take it real slow filling them up, run them in and out 6 times but not right to the stops. The rod movement can be jerky if there is air in there, once it is all oi, the movement should be nice and smooth. Do not stall them out until you know the air is really all gone.