460U hydraulics surging

Got the rebuilt generator on w/regulator "tuned" correctly, now the hydraulic system is pulsing and making a surging sound. The large hydraulic hose running up from the left side of the tranny housing pulses. I checked, there is fluid running out the check plug under the left foot rest and previous owner stated it was changed last year w/filter. Using the quadrant to run the hitch up/down, the system doesn"t have any fits. I"m guessing the screen in the priority valve has got some "foreign material" in it. What say anyone else? Thanks for any input.

Does it get better when it warms up. I'd look at the screen and filter. May have enough water and gunk that it freezes and doesn't allow full flow to pass to the pump. That tends to make it cavitate.

If that isn't it, then look for a blockage somewhere that is causing the relief valve to keep engaging such as the valve you suggested.

Or there is air leaking around the shaft in the tranny housing causing it to cavitate and filling it up with a few extra gallons of hytran fixes that.

Let us know what you find. I start with cleaning the filter and screen and then add extra fluid before tearing valves apart.

bc, thanks so much for your reply. Your wise advise is the route I"m a gonna take. Despite what previous owner stated, I think it best to drain fluid/change filter and see it there is ice/water in the tractor. Fluid appears tan colored that I ran out of check plug. I moved it into a garage I can heat, last evening. That hydraulic system fluid is $$. Dealer said $8.99/gal. and Farm~Fleet in Onalaska has sale ending this weekend, $29.99/five gallon. Would like to support the dealer, but that big a $ difference...well, I"ll just get the filter there. Thanks again bc.

Some of the rich guys use caseih hytran. I use the 303 hytran sold by orscheln in the yellow buckets. When on sale, it is about $23 and regularly around 30. When you look at the specs, it meets ih, jd and other standards. TSC never has their hytran very cheap. Walmart carries it to in supertech with the same specs but not as cheap as Orscheln on sale and I think more than 30.

You for sure want to pull the plugs under the tranny and the rear end to get rid of any water and sludge. Its near impossible to keep fluid from being milky unless you are plowing all day with it to heat the oil enough to get rid of the water. The other problem is that the rockshaft housing under the seat probably has a couple gallons and a bunch of sludge in the bottom of it. Between that and the fluid in the system, you never get it perfectly clean. Most just live with the milky fluid unless it has so much water that it has a pukey slick greasy feel to it. Ih dealer told me it takes 2 or 3 changes to clean it up anyway.

To burp the water out, leave the fill and check plugs tight. When you remove the bottom plugs one at a time it will dump a quart or two and stop for a split second to allow air to get by, then you can stick the plug back in when you just have oil coming out.

When you pull the cover off the filter, it may dump a pint or two there.

I use Wix hyd and oil filters from Oreillys who usually stock them or can get them in one day and they are cheaper. I think IH's are made by wix anyway as they look the same.

If your fluid is just tan colored, I'm not sure I'd mess with changing it all right now. Winter is the worst time for condensation in the tranny and rear end to just add more water anyway. That and melted ice and snow and then rain that gets in around the gear shifter unless you keep it covered as well. I'd just make sure there is no water in the bottom and the filter and then wait till summer.

As you may notice from reading the threads around here, everybody has trouble with their hydraulics until the fluid warms up. Mine has taken from 15 to 30 minutes to warm up enough to quit whining. Cleaning my filter screen stops the surging if that gets bad.


I owned a 460 once and never changed it. It leaked so bad all I did was keep adding to it.