White 2-85 Hydraulic Pump

[Trevis]

Wondering if anyone can Help? I have a 1981 White 2-85 with 8500 hours. The Hydraulic pump quit working, just prior to this happening, the pump started making a noise as if it was starving for oil. I installed a new (re-built) hyraulic pump, but the noise coming from this new pump is the same as before (like it is starving for oil and chattering). I've replaced the oil filter and used fresh oil, I'm using a 22 weight hydrauilic oil since it is wintertime. There is a butterfly valve on the oil filter head that is used for bleeding out the air. When I crack this valve open the noise stops but I have no hydraulics at all. When I tighten this valve the starving noise starts and I have minimal hydraulics. Also, when I pull the dipstick to check the oil, the oil is foamy/bubbly like it is getting injected with air. I have been told by my local dealer that there is no lift/charge pump in this model of tractor. Also I've been told there is no other oil filters to change. This model has a seperate oil resevoir that holds 32 litres (7 gallons) of oil. Can anyone explain what I should try next?
 

[bison]

Sounds like an airlock or obstruction on the sucton side.
Also could be the relief )on front of pump)valve stuck,broke spring or in need of adjustment
lastly the priority valve on the side in front of pump has an issue
 

[Trevis]

I'm thinking that since both pumps (the old one and the new one) are making the same noise, that I should be looking for something else. I've unhooked the suction tube (between the filter head and the resevoir).And blown air through it back into the resevoir. It is not plugged.
 

[Alan K]

Im not that familiar with the 2-85s but my cousins 2-135 has a "whine" in it which I think theirs might be a vibrating line somewhere. Noises pop up everywhere. Does the pump operate ok otherwise?
 

[Trevis]

No, this new pump does not work. With the butterfly valve closed the pump squeals but no working hydraulics. With the butterfly cracked open a 1/4 turn, the noise stops and still no working pump.
 

[bison]

[Wrenchbender]

Did you fill the pump with oil before you installed it? Have you loosened or removed the small case drain line on the pump to bleed air out or see if there is any flow from there? Those systems are hard to bleed out sometimes. WB<><.
 

[J. Schwiebert]

To me that is the best advice so far. Also you should loosen the pressure line 1/2 of a turn to help bleed the pump. Also the 2-85 tractors have a G-rotor pump as a charge pump. You need to have the pump full of oil before you start and you need to make sure the pump is pumping oil before any adjustments are made. The spring(s) move the swash plate to full stroke, the pressure relif valve pushes it back to neutral. I need to think on it little more. It has been too many years and probably worked on less than 20 of them so I need to double check some things. J.
 

[SteveGr]

I had this problem on a 2-105 and thought the new pump was bad. Tried another one same thing. I then took the combination valve off and took it apart and there was the problem. The bypass valve was stuck partly open from debris from the first pump failure. Cleaned it up and resealed it and worked like a charm.
 

[Wrenchbender]

That gerotor pump is only the cooler transfer pump.

The suggestion about metal in the unloader valve would be the next to look at. WB<><.
 

[detroit 2-stroke]

Like steveg said more than likely there is metal lodged in the unloader valve. As a rule of thumb you should always remove the control valve assembly on any white or oliver closed center system after a pump failure since that is the first place the metal goes when the pump comes apart.Besides the o-rings are probably cooked from the heat a worn out pump creates.Also the emergency relief valve in that assembly tends to beat out the shims in it.Then your emergency relief pressure is lower then your compensator pressure and that creates all kinds of problems.
 

[Trevis]

Thanks everyone for all the suggestions so far. I have tried some of these, but still no luck. I will try all of these suggestions over the next couple of days (only get the evenings to deal with this). Does anyone have knowledge on a keyway on the Gerotor Pump. I've been told that maybe before sliding in the new pump the keyway may have been missing or sheared. ????
 

[2-strke detroit]

It is possible that the gerotor pump key is sheared but on this tractor all that pump does is circulate oil threw the cooler and back to sump. So the only thing that would cause is over heated oil. On the 135 and larger tractors the gerotor pump does charge the main hydraulic pump but it is only for cooling on the 110 and smaller tractors. The bleed screw above the hydraulic filter should only be opened with the tractor shut off!
 

[Trevis]

Ok, thanks to everyone that has helped me out. I got my tractor going tonight. The problem was debris in the pressure valve down stream from the hydraulic pump. I took the valves apart today and cleaned out some schrapnal from the old pump that was lodged inside. The new pump is quiet now, for the most part. When the tractor is idling it is quiet, when I turn the steering wheel it is still quiet, but when a lift my front-end-loader it makes a little bit of noise but nothing like before. Thanks again to everyone. Trevis (from Saskatchewan).