460 farmall hyd. problem

11Zach · Jul 12, 2011

I have a 460 and soon as its fired up the hyd. pressure goes up and does not bypass. i have have the releif valve out and cant find whats wronge. the tracto is laboring until i use the 3 point or the implament. please help me on this one thank you

IaGary · Jul 12, 2011

When our 460 did that it was because the top stop on the 2 pt hitch lever was set to high and it would try keep pressure on the top side of the cylinder, trying to raise it past the stroke of the cylinder could. Cylinder was topped out.

Moved the fast hitch lever back just a little and all was fine.

Gary

Owen Aaland · Jul 12, 2011

Check the orifice/screen assembly. That is what provides the control circuit for the unloader valve. If you do not have enough flow through the orifice the system will stay on high pressure.

11 Zach · Jul 12, 2011

I have replaced screen and orifice, still same resault. i was told something about gears in the first hyd. block but havent tackled it yet.

pete 23 · Jul 12, 2011

If the hitch works, and is following the lever the gears are not the problem. Also, if it goes on demand when hitch is in midstroke adjustment of hitch linkage is not the problem. Have you made double sure the pins where you turn your other valves to single and double action are not broken or bent. Some times when they break people turn them too far and bend the internal link. I you have broken or bent pins you can turn the adjustment until you find the sweet spot to go off pressure and work from there.

11Zach · Jul 13, 2011

Tractor is not equiped with fast hitch, it was a store boughten three point. the hyd system is not set up with that rod. thank you

IH fan · Jul 13, 2011

Your main, or master relief must be okay... have you put a gage on it to see how high it goes? If it goes to the factory set relief (my guess), the relief is okay... if it were locked up, the pump (or something else) would blow up. Most reliefs are designed to minimize this happening, they will [u:8ccea401dc]usually[/u:8ccea401dc] go LOW if there is a problem.
If there is an "unloader valve" as Owen indicated, I'd be looking there... it should be going to a low "stand-by" pressure when none of the spool valves is actuated.

pete 23 · Jul 13, 2011

Ok, then the valve that is operating the hitch has a double single action adjustment on it . Check that out first, really simple and many, many are the culprit. It has a roll pin that goes through the adjustable stem or rod on valve and it has a marking of s and d with a stop so it can only go so far. They get bent or broke and then will stay on demand when turned past intended point.

11 Zach · Jul 13, 2011

The roll pin is missing. that might explain alot. thank you very much for your insight. i will replace it and see what we get. thanks again becouse if i had to tear into that valve agian, i just might sell it.

460 farmall hyd. problem

11Zach

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IaGary

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Owen Aaland

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11 Zach

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pete 23

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11Zach

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IH fan

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pete 23

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11 Zach

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