I'm working on a John Deere 500A backhoe that has been parked for about 5 yrs. The owner ran it out of fuel in a garage and has sat since. I had to rebuild the injection pump to get it running again. Now that it is running, there is no hydraulics. Nothing works, power steering, trans, bucket or hoe. Fluid level is good and front shaft is driving pump. I'm a retired mechanic and I'm not afraid to tear anything apart, but I'm not an equipment mechanic. Any input on where to go from here would be greatly appreciated.
i haven't worked on one of those for years but if i recall, they have a radial variable displacement pump. you either have no charge pressure or the stroke control valve on the pump is stuck
Check the pump coupling on the front of the crankshaft to determine if it is tuning the pump.
Thanks for the replies. Are we talking about the pump mounted on the front of the machine? The shaft to the pump is turning, but I haven't crawled underneath to see if the pump itself is turning. Does that pump also control the drive? I'll be back at it Monday morning.
I can't tell you on a 500A, but JD had other backhoes that the transmission pump supplied pressurized oil to the front hydraulic pump. That's called charge pressure, and the transmission won't work without pressure, the transmission has priority, so the transmission will get all the pressure it needs before any goes to the hydraulics. You can tell by looking at the front hydraulic pump if it has the charge pump mounted on the front of it or not. It probably has capped test ports to check the charge pressure, but you already know there is none if nothing works. You might have to drain the oil, find the screen and check it, change the filter and check the old one for debris. You could try loosening the drain plug to see if there's any water that seeps out.
Thanks Delmer, that gives me a place to start. Everything worked when it was parked inside, but it has been sitting for years. When I tore down the injection pump everything inside was gummed up and stuck. A good cleaning and rebuild kit got it running again. I'm hoping that's all that is wrong with the hydraulics.
I seem to recall that that machine had a power shift transmission or collum shift . So the transmission pump is likely not operating as it provides control pressure to the transmission and charge oil to the hydraulic pump. There is a pump inlet suction screen that may be stopped up. If the transmission pump turns to long with out oil it can be damaged. Number 26 for powershift and number 5 for collum shift
Welcome to HEF BEK ! The first thing I would check is your engine clutch( do you have a powershift transmission or a collar shift?). If the machine sat a long time and the clutch pedal was pushed all the way down to disengage the engine clutch (powershift) or PTO clutch (collar shift) then maybe the linkage/clutch is now stuck in the disengaged position. You will lose transmission pressure and that also means no hydraulics.
There is a transmission disconnect lever in the side of the dash make sure it's in the correct position at least on a 510 there is I think a 500 does too with it disconnected you will have nothing working
It has a clutch pedal so I assume it has a powershift. The pedal was in the return position, but I will check that first. It has a flat handle on the side and to the left of the steering wheel/dash area that only moves slightly forward & backwards. Also a short flat handle on the floor area under the seat and to the left that doesn't move. I don't know what either of those handles do. I'll check the pedal then move on to the suction screen. Where is in relation to the hyd filters? I'll plan on changing them also.
Ok I was writing when the disconnect lever message was posted. Forward or back to engage the trans?
Tyler d4c I'm in Windber,Pa
PM me I'll come have a look sometime and help you figure out
The lever is the clutch disconnect for the powershift transmission. Forward position should be clutch engaged, pulling it towards the seat would be clutch disengaged.
Thanks to all that responded to my question. I got the hoe operating today. Simple fix, it was the clutch disconnect lever. I didn't understand why such a heavy built lever would only move an inch or two, so I took the cowl panel loose to see what it was connected to and found the lever had a stop to keep it from going in the engaged position. Stop was connected to a knob on the dash. Pulled the knob and pushed the lever, everything works. I ordered a manual and plan on doing a full service on the machine. Thanks Again To All
Best item I ever bought for my 310A was a factory service manual. It has saved me a lot of time over the past 6 years answering questions amd troubleshooting issues.
I guess you dont need me them but if you ever need a hand just ask I'm not far.
Hey BEK! I just bought a 500 industrial yesterday and low and behold the guy got rid of it because "all of the hydraulics failed" it was the same issue, he didnt know how to run the machine. I didnt either, i found that lever by accident once i lifted the cowl just snooping around. Curious on which manual you ended up getting, and if you found it useful. This is my first machine, and it needs a lot of love. Best, Sean
I never got the manual that I ordered, guy said he sold it before I ordered. I wanted an old factory original one. I started using the machine and it's been working so well I never got around to looking for another manual. Something I really need to do just in case.
BEK, you don't really need factory original, there are many quality reprints out there reasonably cheap...just do the search...when you have the service and parts manuals your equipment experience will be so much easier....and easier to get parts either online or at dealer if you have the oem numbers...