farmall 460 hyd system overheating and surging

redhot · Sep 20, 2010

The tractor runs fine but after 45 min to 1 hour the transmission case gets hot and the hyd pump seems to be blowing over relief. So I took the pump regulator apart and found the orfice plug for the unloader valve was plugged. so I unplugged it,clean and checked the other valves in the regulator and assembled regulator. Ran tractor found no difference. I checked the other control valves for proper one or two way flow detent postions, they were okay. Installed two new suction filters. Ended up taking out the spring for the unloader valve in the regulator. this seemed to stop the problem, but do not have hyd pressure for remotes. I would like some help to find root cause for the problem.

Anonymous-0 · Sep 20, 2010

The regulator & safety valve (IH terminology) is the 4 bolt square capped valve in the stack ahead & below the dash, it has the small screen that screws in, also a regulator valve that must operate freely, also piston with oring on it, then if fast hitch equipped the differential gears timed & working on the valve for hitch. It sounds like the regulator valve is stuck from a chip or rough edge, take crocus cloth & polish it. 460/560 Farmall same with PS & FH.

pete 23 · Sep 20, 2010

Question, you stated you took the orfice plug out and cleaned it in regulator valve assembly. Did you cut the end of the screen off so you can clean completely and then roll it back up a bit. Also, did the orfice have a roll pin in head, if so there is a ball under that pin and it bounces back and forth over time and peens the hole undersize. They are hardened and very hard to drill out but I have done it. Just did it to a 560 couple of weeks ago. The original size of hole is .031 so not very big. As the regulator lands on the aux valve and especially the teledepth valve if it has fast hitch wear, they allow more oil to flow past them than what the orfice can supply to regulator piston there fore you go on demand and system will of course heat. I have drilled many over size but it is trial and error. Too much and you have no hydraulics. I would strongly recommend you put a gauge in port right on main pump to observe regulated and relief valve pressure. Often times they will work fine until warmed up and then go on demand and stay there.

farmall 460 hyd system overheating and surging

redhot

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Anonymous-0

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pete 23

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