b3030 hydro oil

firedave19 · Jul 13, 2011

Is it normal for cylinders and hoses to be almost impossible to touch because they are so hot after a few hours of digging on my b3030 backhoe

kuboman · Jul 13, 2011

firedave19 said:
Is it normal for cylinders and hoses to be almost impossible to touch because they are so hot after a few hours of digging on my b3030 backhoe

Heat kills hydraulics dead. Seems unusual for them to get that hot but also you are using a consumer product for industrial purposes. These tractors are meant for intermittent use. I would engineer a better oil cooler.

Farmerford · Jul 13, 2011

Yes, they do get that hot. I have an old B2400 and a newer 4330, both HST and both with FEL's but not backhoes. When the FEL is worked hard the valve block is too hot to touch for more than a second or two. And your backhoe probably heats up the oil more than my FEL and HST together because backhoes seem to spend a large percentage of the working time against the stops; it with the pressure relief valves flowing, which really heats up the oil.

But the proper hydraulic oil will maintain sufficient viscosity to keep rubbing surfaces apart even at 100 deg C, which is whole lot hotter than it gets in the tractor. Likewise, proper hydraulic oil does not oxidize very rapidly at temperatures below 100 deg C, so the temperatures you are feeling do not significantly shorten the oil's life.

There are charts somewhere on the Internet that show how long you can touch different surfaces at various temperatures; I vaguely recall that 150 deg F metal is too hot to touch for more than a second or two. And the hot water from most hot water heaters is 140 deg F or less. Run a metal pan full of hot water from a tap near the hot water heater and feel the pan; I suspect it will be hotter than your hydraulic valve.

Better yet, buy an inexpensive infrared thermometer for an accurate reading of the valve body.

firedave19 · Jul 13, 2011

Thanks for info just first time I ever had a machine like this just was wondering

Verticaltrx · Jul 13, 2011

kuboman said:
Heat kills hydraulics dead. Seems unusual for them to get that hot but also you are using a consumer product for industrial purposes. These tractors are meant for intermittent use. I would engineer a better oil cooler.

When you work them hard in warm weather the hydraulics on the Kubota Industrial TLB's get just as hot. In fact that's the case with about any backhoe, loader, dozer, etc etc. Just the nature of the beast, I wouldn't worry about it.

Toolguy · Jul 13, 2011

What Verticaltrx said is true. It sounds like your machine is working just fine.

kuboman · Jul 13, 2011

An infrared thermometer will tell you the temp in a second. Do an internet search on heat and hydraulics and you will find that 140* is the top end for a sustained temp. Anything over that and the life of your components is shorted.