Help me. The bucket cylinder stays at the end of the stroke in the digging direction and does not move. Even if the bucket cylinder is operated in the dump direction, it does not move Pilot oil pressure at stroke end is normal in digging direction and slightly high in dumping direction
Good day Seal falure will always cause the the cylinder to extend as it has the larger surface to work with, have you checked out the cylinder? Bucket cylinders are the most prone to damage. Kind regards Uffex
thank you. But the bucket cylinder has no issues. Sounds like a problem with the control valve.
This sounds like a plunger on your manipulator may be hung or stuck from dirt or contamination. Remove the boot and see if the height of the plunger tops may be off on your bucket curl.
thank you. But the pilot valve is fine. Pilot pressure to control valve is normal. It looks like the control valve spool is not moving.
Good day A method of checking out the spool is to pressurize one end while measuring the other, the spool will most likely only shift 10-12mm but it will tell you if the spool is shifting. See attached will give you the principle, if you cannot get in with a vernier use a stud with a nut. Kind regards Uffex
thank you. However, the pilot pressure of the control valve spool of the bucket cylinder could be confirmed with the monitoring function of the monitor. At the stroke end of the pilot valve, the pilot pressure on the dump side slightly exceeds the pilot pressure on the bucket curl side. I feel that the spool of the control valve does not move due to the load.
I had a similar problem with bucket of 966h loader not reaching the top and slow movement while loaded, removed the control valve block completely, took it apart, found some metal and damaged seals and extreme dirt. Cleaned, replaced all the seals, replaced two relief valves and all went well. thought this might help
Good day The display information only confirms pressure, not movement. Kind regards Uffex
So why haven't you pulled the spool . You've shot down every suggestion that is quick, cheap and easy. Pull the spool and be done with it.
Do you have raised pump pressure with the safety lever down? That would indicate that your spool is shifted and you are sending LS to the pump. That's pretty simple, right?
I think you are getting a circular reference. I didn't answer because I figured this was going to go in circles.
Good day Confusion one leg in Japan the other in Saudi or are we answering different folk on the same post? Kind regards Uffex
I think the Saudi guy was offering his experience with a very similar situation. In regards to our friend in Japan, if the pilot sensor is only showing a "slight" increase when the joystick is stroked fully says that either the joystick valve is defective and should be inspected per Vetechs suggestion or there is debris or obstruction in the pilot signal to the spool cap. If I were doing that job, I would physically gage the pressure to each spool cap, not just rely on the sensors which could be defective. If I were seeing good pilot oil at the spool cap, I would proceed to remove the spool. But first I would observe pump pressures. If one or both is raised beyond standby (unload) that would tell me that the spool is bound in a shifted position. OP stated that he thought the load could be holding the spool. That can't happen. That's what the port relief valve is for. That and it's not physically possible to lock the spool with hydraulic oil on the load side. Good luck to OP
Thanks man. Appreciate it