Lost hydraulics on my John Deere 410c the other day after loader slammed back a little hard. I think or hope it's the destroker but not sure of location of destroker nut on pump.
I think that pump has an electric destroke solenoid, if there's an electrical wire going to the front hydraulic pump then that's the destroke solenoid. But I don't think that's the problem, maybe not what you're talking about either? The other destroker controls crankcase pressure continuously to control the pump output. That is a threaded adjustment with a locknut going into the other side of the same 'bore" as the destroke solenoid. At least look it up on JDparts.com so you know what pieces to expect when you pull it apart. Do your brakes, steering, and backhoe work or not? Have you looked to see that the pump input shaft is turning?
There will be a small threaded rod with a "T" pin at the top for manually destroking the pump, either alone or in combination with the solenoid I think. If other systems work, deadheading the loader bucket may have caused the pressure control valve spool to travel farther than normal and stick?
Thanks so much guys great information. I'm so glad I found this site. On the road today so haven't had much time to work on machine. It is electric solenoid on pump. I think maybe manual destroker is on the opposite side of solenoid? Also I have forward and reverse, no steering though. But I think 410c has separate pump for transmission. Going to check power to sloenoid tonight. I have had ground issues on machine before. Just trying to eliminate the simple stuff before I tear pump out.
Power to the solenoid shuts off the hydraulic pump, you should only have power to that solenoid when the engine is cranking. Disregard what I said about the location of the solenoid and stroke control valve, I was mis remembering. The stroke control valve (on top of the pump and close to the destroke solenoid) is the prime suspect, if the pump shaft is turning. You can take that off the pump relatively easily and inspect for debris. Did the "loader slammed back a little hard" happen normally? Did it slam back the same as you'd expect it to at the end of the stroke? or did it seem to slam harder than it normally would?
No it always slams back hard if I'm not paying attention. I had dumped a load and was looking down while rolling the bucket back and wham. Stopped motor and I.had to play with hydraulics while cranking over to start . Which has happened before but never lost hydraulics.
Also pump is turning , and no backhoe, steering,or loader operation. Pump gives a little knock sound every couple of seconds almost like it's destroker,just not sure with jd. Had a kabota that would knock a little in destroker.
Finally got to machine today. Removed solenoid and everything looks ok. Not sure where priority valve is though, would like to check that.
Or stroke control valve like seller said. Not sure exactly where that is either
I meant like delmer said
Where did the priority valve come up? The stroke control valve is on the hydraulic pump, opposite the solenoid. Not one any of the 8 radial hex caps. If you post a pic of the top of the hydraulic pump, we can point it out.
Thank you delmer I will send a picture soon. Haven't had time to get to machine. Hay is on the ground and rain is on the way. Will get back to machine soon as we're done and I'll keep you guys posted. Probably Wednesday I'll be back at it. Thank you guys again.