Machine has no stick in digging power. Pump 1 and 2 pressures are spec as are pilot pressures on stick 1 and 2 valve bank. Regen valve and reliefs are new. Checked all load checks and NFC valve. All good. Drift reduction valve is good as well. All other functions work good and cycle times are good. There is a "grumbling" in the stick lines when bringing in. Cylinder is new as per an update as is the slow return check valve. Kinda lost at this point. Any help is appreciated
Hey j I'd try using a temp gun to find the leakage. I'd cap the line and see if it builds relief pressure both directions. I'm leaning towards cylinder I had a d8t bolt backed off for blade lift cylinder the blade intermittently fell for two weeks before piston fell off. Good luck and keep us posted
I ruled out the cylinder. I replaced it after problem had started. It has a growling in the lines and saw some scoring on the piston. Found stick cylinder had an update for the snubber ring failing. This cylinder didn't reach failure. Slow return check and regen valve are both new as well
Was there contaimation from scoring? Did you inspect main spool for stick? Possible pilot issue on control valve?
Pulled both stick 1 and 2 spools. Look as new and move freely. Pump 1 and 2 are at 5100 psi pilot pressures are all equal 400+ psi. Pulled all valves we could with control valve in machine. All clean and free. Pressures are all there.
Do you have access to a flow meter big enough to flow stick circuit ?
That was next move when it comes available. The way it sounds when you stick in is that the rod end is fighting the head end of the cylinder. Pumps go to max pressure and sticks slow
Pressure on both sides sounds like main spool travel.
How would you check for that in machine? That's just the best way to describe the actions.
Take the line off cylinder put pressure gauge in each line and cycle stick in see what pressure is on each side
Have to see if I can get some fittings to "t" into it. Won't be back at it till Monday at earliest.
Check the stick drift reduction valve. Sounds like it isn't opening. Recheck regardless of weather it was just repaired or not. Something is holding oil in the cyl. Later Bob
Has the machine got hose burst protection valves fitted?
Drift reduction was checked twice and all free and looked good but ill give it try. If by hose burst protection you mean relief valves those are both working fine. Is there any possibility there's an issue with the handle?
Is there any sort of hydraulic valve/manifold looking thing mounted on the stick cylinder? If so, that's a hose burst protection valve. If you have one on the stick cylinder, you'll find a pair on the boom cylinders as well. If you do have them fitted, I'll bet you 5 euro that is the problem.
Machine doesn't have the load valves on the stick. Just tubes and hoses.
To eliminate the pilot system, exchange the stick pilot lines at the main control valve. The control will now work back to front, but if you still have a problem with stick in you now know it's not a problem with the pilot valve. What's your serial number?
Eeh is the serial number prefix