This is from the farms 1973 International tractor having a separate hydraulic oil tank and a gear pump in an open center system. The filter is located on the pressure side of the pump. When the ambient gets in the low 40s, the pump starts whining even at modarate loads, such as raising the empty front end loader. At no load, when the pump just circulates the oil through the filter and the valves, everything is quite. That makes me believe the filter is not clogged. It is obvious that the noise is visc/temp related. That said, the oil (a mix of Case IH Hy-Tran Ultra and some 10w-40 HDEO make up oil) is normally not considered too heavy for this application. What makes a gear pump noisy?
Gear pump noise - reasons... viscosity ...and?
- Thread starter Extreme-Duty
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Does it get better after running it for awhile? (ie after the oil warms up?)
when was the last time it got a new filter? and by pressure side do you mean return line?
How fast is the engine running? Does changing engine speed effect the noise?
I would run straight hytran or engine oil and not mix them. But you are right on old farm equipment engine oil was spec for hydraulic systems.
Does it have a filter on the suction side? Maybe an in tank filter screen?
when was the last time it got a new filter? and by pressure side do you mean return line?
How fast is the engine running? Does changing engine speed effect the noise?
I would run straight hytran or engine oil and not mix them. But you are right on old farm equipment engine oil was spec for hydraulic systems.
Does it have a filter on the suction side? Maybe an in tank filter screen?
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Originally Posted By: Texan4Life
Does it get better after running it for awhile? (ie after the oil warms up?)
when was the last time it got a new filter? and by pressure side do you mean return line?
How fast is the engine running? Does changing engine speed effect the noise?
I would run straight hytran or engine oil and not mix them. But you are right on old farm equipment engine oil was spec for hydraulic systems.
Does it have a filter on the suction side? Maybe an in tank filter screen?
+1 all the above posted. How old is the oil.
Does it get better after running it for awhile? (ie after the oil warms up?)
when was the last time it got a new filter? and by pressure side do you mean return line?
How fast is the engine running? Does changing engine speed effect the noise?
I would run straight hytran or engine oil and not mix them. But you are right on old farm equipment engine oil was spec for hydraulic systems.
Does it have a filter on the suction side? Maybe an in tank filter screen?
+1 all the above posted. How old is the oil.
trimmed a bit by George ...
Originally Posted By: Extreme-Duty
When the ambient gets in the low 40s, the pump starts whining even at moderate loads, such as raising the empty front end loader. At no load, when the pump just circulates the oil through the filter and the valves, everything is quiet. It is obvious that the noise is visc/temp related. What makes a gear pump noisy?
A pump will sound much better in cavitation conditions with low outlet pressure than with high outlet pressure; that answers part of your question.
In my opinion, you are using too viscous a fluid for those temperatures. Your mixture may hurt some too. I don't know the manufacturer's specs, but for outdoor equipment, I'd personally run an older clone of Dexron II or III (NOT Dexron VI) ATF. If I wanted to run engine oil, it would be a 0W20 or lighter if I cold find it.
Originally Posted By: Extreme-Duty
When the ambient gets in the low 40s, the pump starts whining even at moderate loads, such as raising the empty front end loader. At no load, when the pump just circulates the oil through the filter and the valves, everything is quiet. It is obvious that the noise is visc/temp related. What makes a gear pump noisy?
A pump will sound much better in cavitation conditions with low outlet pressure than with high outlet pressure; that answers part of your question.
In my opinion, you are using too viscous a fluid for those temperatures. Your mixture may hurt some too. I don't know the manufacturer's specs, but for outdoor equipment, I'd personally run an older clone of Dexron II or III (NOT Dexron VI) ATF. If I wanted to run engine oil, it would be a 0W20 or lighter if I cold find it.
MolaKule
Staff member
I assume we are discussing a fixed-displacement gear pump.
You may have internal leakage due to a worn pump, as per worn chambers, worn sideplates sometmes called "pressure plates," or worn gears.
You may have internal leakage due to a worn pump, as per worn chambers, worn sideplates sometmes called "pressure plates," or worn gears.
Thanks for all your suggestions. My original thoughts were much like that, but I did not know where to start splitting the tractor apart. In the meantime I found an older discussion on a red tractor forum. One guy had similar temp/load dependant noises from his pump, which were resolved with a shaft seal replacement. For now I have to believe the pump sucks air (and a bit of oil) from the timing case housing. What confirms this is the foamy oil and the slow warm up. Recently, my dad used the loader for about 30 minutes and the hydraulic pipes stayed "cool". Once the system is warmed up, it does not lack any power and is quiet imo. In other words, it might not be too late yet, but if we leave it this way, the pump will suffer what Mola said.
Needless to say, the oil is junk by now. The tank has a screen in it and there is a filter cartridge in the pump outlet line, both will need some attention.
Originally Posted By: George Bynum
trimmed a bit by George ...
Needless to say, the oil is junk by now. The tank has a screen in it and there is a filter cartridge in the pump outlet line, both will need some attention.
Originally Posted By: George Bynum
trimmed a bit by George ...
Extreme-Duty said:
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OK,the shaft seal and the "cover seals" have been replaced and the noise has gone. Wear wise, the pump housing and bearings looked far from good, but still seem to get the job done on this nice, handy, 37 year old tractor.
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