What temperature for hydraulics?

[fishmanwill]

Good afternoon, I just got my new to me Ag King 2840 (jinma 254) up and running. Had to get a new hydraulic pump and many other new hydraulic parts. I took out the quick connects for the FEL and went to straight swivel. Fluid is changed and filter is new. Ran the tractor,FEL, 3PT, and drove the tractor for the power steering to get all the air out of the system and to make sure everything was working. After shutting it down after 10-12 minutes of running everything, the pump felt really hot, so I got a digital thermometer and read the temperature on the pump and it was 200-215 degrees F. The current ambient temperature is 100.

Is that too hot? If so what should it be and what would cause the high temperature? Thanks.

 

[CalG]

No, It's not too hot.

Well, the 100 ambient IS too hot, but that is a different issue. ;-)

eta
Temperature Stability of Lubricants and Hydraulic Fluids


"air to oil coolers fail just when they are needed most. When the ambient temperatures are high" . para phrased, but you get the meaning.

 

[oldnslo]

200-215F is getting close to the upper limit of operation for the oil and seals Pressure drop or pressure loss causes heat. Can you check the pressure at the pump outlet or some place close to the pump outlet with all the valves in neutral.

Best guess it should be around 300 PSI

 

[IceStationZebra]

In an ideal world hydraulic oil would be kept under 180°F because every 18°F/10°C over that the life of the oil gets cut in half due to oxidation. As we know mobile equipment often exceeds this, but the life of the oil may already be limited due to water or contamination. And don't forget that hotter oil is thinner, which results in slightly more wear. (even though most happens at start-up)

And like oldnslo says the next concern is seal and hose degradation. Low end NBR is good to 212-250°F, depending on manufacturer, but again every 18°F over 180 is halving the life (basic chemical reaction). Sometimes valves use HNBR seals as a step up and they are good for 260-325°F. Your system wont burst into flames, but you will need to replace parts sooner and may experience seal weeping.

The other thing to be aware of is the proper use of the magical IR temp gun. First you will not get a good reading from plated fittings, machined aluminum or other shiny surfaces unless you can change the emissivity setting. The best bet here is just measure an adjacent rubber hose or painted surface. The next option is to paint the part or cover it with tape. Second think to be aware of is that the further away from the target the bigger the area that you are measuring. Some guns have a diagram molded into them that shows this. If there is any question get the gun as close to the surface as reasonably possible. And lasers are an aiming gimmick - you can not measure a 1mm spot at 5ft. My buddy calls doesn't call them "random number generators" for nothing!

ISZ

 

[CalG]

In an ideal world hydraulic oil would be kept under 180°F because every 18°F/10°C over that the life of the oil gets cut in half due to oxidation. As we know mobile equipment often exceeds this, but the life of the oil may already be limited due to water or contamination. And don't forget that hotter oil is thinner, which results in slightly more wear. (even though most happens at start-up)

And like oldnslo says the next concern is seal and hose degradation. Low end NBR is good to 212-250°F, depending on manufacturer, but again every 18°F over 180 is halving the life (basic chemical reaction). Sometimes valves use HNBR seals as a step up and they are good for 260-325°F. Your system wont burst into flames, but you will need to replace parts sooner and may experience seal weeping.

The other thing to be aware of is the proper use of the magical IR temp gun. First you will not get a good reading from plated fittings, machined aluminum or other shiny surfaces unless you can change the emissivity setting. The best bet here is just measure an adjacent rubber hose or painted surface. The next option is to paint the part or cover it with tape. Second think to be aware of is that the further away from the target the bigger the area that you are measuring. Some guns have a diagram molded into them that shows this. If there is any question get the gun as close to the surface as reasonably possible. And lasers are an aiming gimmick - you can not measure a 1mm spot at 5ft. My buddy calls doesn't call them "random number generators" for nothing!

ISZ

All good comments and information! ISZ!

 

[sd455dan]

Good afternoon, I just got my new to me Ag King 2840 (jinma 254) up and running. Had to get a new hydraulic pump and many other new hydraulic parts. I took out the quick connects for the FEL and went to straight swivel. Fluid is changed and filter is new. Ran the tractor,FEL, 3PT, and drove the tractor for the power steering to get all the air out of the system and to make sure everything was working. After shutting it down after 10-12 minutes of running everything, the pump felt really hot, so I got a digital thermometer and read the temperature on the pump and it was 200-215 degrees F. The current ambient temperature is 100.

Is that too hot? If so what should it be and what would cause the high temperature? Thanks.

So( if) the temp reader is correct- your hydraulic pump increased temp by at least 100 degrees, And it sounds like this happened in a few minutes of operation? The temp rate of increase seems wrong to me...
I think your tractor runs multiple items off of a single pump? i can run all day and not see temps near that hot but have individual pumps for power steering, loader/ remotes, and 3 point.

It might be helpful to T a pressure gauge into the pump output and test to make sure there is not a load against the pump when it should be just circulating the hydraulic oil Open circuit.

Might also be a good test to start the tractor cold and not use Any of the hydraulics and watch the temp increase of the engine block vs. the hydraulic pump most tractors the pump should lag the engines block temp increase if the hydraulics are idle. jmo and :2cents:

 

[RickB]

So( if) the temp reader is correct- your hydraulic pump increased temp by at least 100 degrees, And it sounds like this happened in a few minutes of operation? The temp rate of increase seems wrong to me...
I think your tractor runs multiple items off of a single pump? i can run all day and not see temps near that hot but have individual pumps for power steering, loader/ remotes, and 3 point.

It might be helpful to T a pressure gauge into the pump output and test to make sure there is not a load against the pump when it should be just circulating the hydraulic oil Open circuit.

Might also be a good test to start the tractor cold and not use Any of the hydraulics and watch the temp increase of the engine block vs. the hydraulic pump most tractors the pump should lag the engines block temp increase if the hydraulics are idle. jmo and :2cents:

The second of two very informative and useful posts. I've nothing to add.

 

[fishmanwill]

I did not know that the IR temp gun would not give accurate readings on shiny surfaces or machined aluminum(which the pump is). Thank you for letting me know that. I was able to get the readings from about 3 inches away, but it was on aluminum. so probably not accurate enough. I had to replace some hydraulic hoses and will get a better reading on the hoses or I will put some tape on the pump and try again. Thank you again for the help.

 

[fishmanwill]

sd455dan, The tractor does run everything hydraulic off of the one pump it is supposed to be an open system that runs the FEL, powersteering, and 3pt. I did install after you reply and several other people I talked with a gauge after the pump. The hydraulics are reading 0 pressure when idling so the system is open and there is no restrictions. I replaced a few leaking hoses and will retest and go over the whole tractor this weekend and see how warm it gets. Thanks for the help.

 

[IceStationZebra]

No problem, we are all here to share hard earned wisdom. :groundhog: ISZ