I have a John Deere 490E excavator and everything was working fine all day Then all of a sudden every control was really slow. I can't find the Problem and don't kno much about hydraulic problems but I can figure it Out if anyone has advice on what to look at or where
Check pilot circuit pressure. Filter restriction light on? Fluid level. May be main pump pressure low? I would start with the filters. If that doesnt help check to make sure that the swash plate angle on the main pump is changing as you push the buttons in the cab for your dig settings. May be stuck on low. Has to have something to do with either the pilot circuit or the pump if everything is doing it.
No filter restriction light on. And I checked the filters they look good too. I will check the other stuff you recommended tomorrow. Thank you for your time
Did it work fine the next day? Look up Hitachi 120 problem and you'll find lots of posts, lots of suggestions, not much resolution. You're lucky if it's not intermittent, if you get a mechanic out make sure it's one with proper diagnostic equipment to check the electronics.
Did you find the problem? Mine was working fine shut down went to lunch came back everything works just extreamly slow. I need help I have read most threads not much help my machine very clean and unmolested checked connectors waiting on service manual to arrive. I have extensive background in electrical and hydraulics need book to get started any Ideas?
DP sensor or angle sensor gone bad.