Hydraulic connectors heating up?

[airbusdriver]

Hi all, I have a CT440 with front hydraulic auxillary kit for my tree spade. Everything works fine however I find that after using my treespade for 2 or 3 trees, that the Hydraulic connectors and hoses begin to get quite warm to the touch. I have a 3 spool valve on the tree spade that has an open center. All lines on spade are 1/2 inch with appropriate connectors. I have checked with Bobcat as to direction of flow from the tractor (Female connector is the return) and everything appears to be connected correctly to the spade. Is it normal for the hydraulic lines to heat up? Seems unusual.
Comments would be appreciated.

Dave

 

[CT230 Fan]

Hi all, I have a CT440 with front hydraulic auxillary kit for my tree spade. Everything works fine however I find that after using my treespade for 2 or 3 trees, that the Hydraulic connectors and hoses begin to get quite warm to the touch. I have a 3 spool valve on the tree spade that has an open center. All lines on spade are 1/2 inch with appropriate connectors. I have checked with Bobcat as to direction of flow from the tractor (Female connector is the return) and everything appears to be connected correctly to the spade. Is it normal for the hydraulic lines to heat up? Seems unusual.
Comments would be appreciated.

Dave

I think it is natural for the connectors to heat up some, however, if there are too many connectors in a line, and or turns in the line, you are creating friction in the hydraulic oil, which causes heat. Also if the fitting sizes are too small, it will increase back pressure, which will also heat up the hydraulic oil. I'd check the color of the oil before and after each use. If it starts to get dark or smell different, then I'd start to get concerned, but if not, I think you are ok.

 

[airbusdriver]

I think it is natural for the connectors to heat up some, however, if there are too many connectors in a line, and or turns in the line, you are creating friction in the hydraulic oil, which causes heat. Also if the fitting sizes are too small, it will increase back pressure, which will also heat up the hydraulic oil. I'd check the color of the oil before and after each use. If it starts to get dark or smell different, then I'd start to get concerned, but if not, I think you are ok.

Thanks CT230 Fan, I will keep an eye on the fluid. Between the quick connects on the loader and the 3-spool valve on the spade, I have about 6' of 1/2" line with a 90 degree connector on each end for the supply & return lines. Thanks for the quick reply.

Dave

 

[J_J]

airbusdriver,

I don't know if you know this or not, but the QD should be one size larger than the hose size, to make up for the restrictions caused by the spring and seating assembly. If you can look inside the QD you would see. When you talk about 1/2 inside diameter, you would think that is what it is, but not true in this situation . It is probably closer to 3/8 in. Anything that get in the way of the fluid is some kind of restriction, and heat will be generated at QD, 90 degree or 45 degree fittings, smaller hose, etc. Constantly playing with the loader valve will cause things to heat up. Working the cylinders to the extreme will cause the relief valves to work over time.

 

[Egon]

the Hydraulic connectors and hoses begin to get quite warm to the touch.

If your not burning your fingers it should be good.

 

[radman1]

The hydraulics on my tree spade circulate oil all the time when it is being used. I suspect his is the same. Most tree spades are used on skid steers which have lots of oil cooling and large oil capacity. Most CUTs don't have oil coolers. Some of the heat could be from constant flow. Really need a temp gun to tell how hot the oil is getting. The "hand" thermometer and internet guessing probably won't yeild a real answer.

 

[kennyd]

It is very common for hydraulic fluid to reach a temperature at about 100* above ambient temperature, so 180* oil or so is normal. Naturally, some of that heat is transferred to the metal fittings and QD's.

 

[kennyd]

Most CUTs don't have oil coolers.

I do not agree with that at all...only the smallest SCUT's like the JD 2305 and Kubota BX series do not have coolers.

 

[radman1]

I do not agree with that at all...only the smallest SCUT's like the JD 2305 and Kubota BX series do not have coolers.

I should have put it a little different. Most CUTs do have HST oil coolers. I don't know if they were designed for their hydraulic outlets to be running constantly under pressure. However, many people have backhoes which have constant flow through the system. My earlier suggestion may not be valid. Too much heat in the oil may only be an issue if both the HST and hydraulic outlets are under load. A tree shear would not have any significant HST load when the hydraulic outlets are being used. Again the only way to tell if the oil is too hot is by actually measuring the temperature. $30-40 HF infrared heat gun maybe the best answer.