Hi, I have a 1989 John Deere 510c 4x4 backhoe. I bought a new hyd pump for it and installed it. It worked fine for a several hrs but then the steering got stiff, only the steering. A day later the levers for the backhoe are now very tight. It sounds fine and and has plenty of hyd. power. Just the controls have tightened up. Definetly not right. When on of the control levers is moved, it will often get stuck and taks a bit of muscle to snap it back. I called the company where I got the pump and they said the pressure on the new pump is set too low and I need to adjust it. Would low pressure cause this? I have had machines for many yrs and have never had low pressure do this, but first time for everything. It has pump # RE33603. Thanks very much, Matt
Low pressure setting on the pump doesn't make sense to me, why would it work at first and still have the same power on the backhoe? Did you change the filter and flush anything when you changed the pump? Assuming the old pump went bad, did it send any metal into the hydraulic system?
I changed the filter not too long back so I thought I would run awhile before I changed it again. The pump did not have a catastrophic explosion, just got real weak. Man, when we put the new pump in it ran like brand new. Smooth and fast. About a day of operating into it and these symptoms started. I just came from it and the rear levers are very hard even when cold. Also, the front bucket would not respond. I had to run the back boom in and out and then the front bucket kicked in. I appreciate the help. Matt
Oh, I did have the radiator and oil cooler flushed and cleaned when it was apart. Thanks
This is over my head. Are the levers hard to operate with the engine off also?
You could have an issue with the priority valve. That would explain the steering issue but not the lever issue. There is a screen in the priority valve see if there is metal in that. I would ask the same question as delmer, if the levers are stiff with the engine off.
I went and checked it yessterday and yes the levers are stiff when it is off. I would assume that means debris in the spools. May have to pull them and check it out. Thank you, Matt
If you have metal floating around, there will be "silver frost" in the filter, and in the bottom of the bucket when you drain the oil, or on a magnetic drain plug or any magnet you fish around the "tank". A magnetic drain plug will always have some fine particles on it, but you'll know if it's bad. The filter is easier to get to than the priority valve. If the priority valve was doing anything wrong, the only thing it would do is kill your power steering when the loader is used (taking up all the flow/pressure) just like the backhoe will do when the priority valve is working. Doesn't sound good to me, but see what you find.
No, doesn't sound good. I will pull the filter and take a look. Yes, some metal on a magnetic plug is normal, but I hope I don't have any "beards" on it. I have been through many final drives and trannys on our Cat dozers and have seen some bad ones. Thanks again, time to get dirty. Matt