HST Owners: Are there things to avoid?

[dwelshans]

Appreciate all the input.

Thanks namesray:

"maybe don't hook it up to your newer tractor until just before trans/hyd change time, then hook it up, run it for a short while to get the sudt in the splitter hoses, then change out the fluid in your kubota tractor. now your splitter is all filled with sudt and you are changing the tainted trans/hyd fluid out of the tractor, and putting fresh sudt in it."

...great idea.

 

[powerpace]

Yep. What everybody else said.

 

[MarkV]

I would add to not change gear ranges while on a slope. There is a lag period and the tractor will free wheel if the brakes don't hold it on the hill. Don't ask how I learned that one.

MarkV

 

[Ford tractor]

Other question, who has experience running hydr. implements from other people/tractors? Won't the oil coming out of it cause problems with the oil of the HST? Surely not everyone knows what oil is in the implement

Rgds,
Adryan

Practice "safe implement" You never know what you can get from un-safe fluid transfer -- :laughing: The HST's like a multi-vis 5w30 equivalent fluid (That's what's in SUDT), but many skid steers are full of straight 30wt hydraulic fluid. It won't kill your tractor, but if you thicken the fluid in the summer, it could give you issues in the winter.


There is one for sure 100% thing you should NEVER do. That is shift the range while moving. ONLY shift ranges with the tractor stopped. I think the book says stopped and clutch down but.... I don't always do that:ashamed:.

 

[techman]

Since hydraulics are my occupation, I guess I can comment.

There is little you can do to a hydrostatic to cause it any harm. Keep the fluids full and clean. The only "bad" thing is to stall the drive. As stated, if you lug and stall the hydro, all of the energy out from the hydro will go into heat. You can do this for short instances, but a prolonged stall will overheat the fluids and seals and cause potential damage. So if the torque is marginal, use a lower gear.

paul

 

[InThePines]

Since hydraulics are my occupation, I guess I can comment.

...The only "bad" thing is to stall the drive. As stated, if you lug and stall the hydro, all of the energy out from the hydro will go into heat. ....

paul

I am not familar with some terms that many may understand, please tell me what stall the hydo means and how you know when it is happening and if it happens all at once or something you build up to or what. Thanks.

 

[k0ua]

I am not familar with some terms that many may understand, please tell me what stall the hydo means and how you know when it is happening and if it happens all at once or something you build up to or what. Thanks.

Lets say you are hooked to a big tree with your drawbar, and you have some really good traction, and your running a lower rpm. You press the forward pedal, and nothing happens, the wheels dont spin, because you have excellent traction, and the RPM is low. The tree does not move, and like a dummy you just sit there with your foot on the pedal and nothing is happening. ( I know you would not do this) The engine is still spinning the hydro pump. and pumping energy into it, but the hydraulic motor is not moving and the fluid is just heating up. (this is what he warns against) This is similar to in an automatic transmission when you "power brake" by pressing the brakes, and the accelerator at the same time, the engine is spinning the torque converter and it is in a stall condition because the transmission cannot move due to the braking . For a short period of time this is not going to tear anything up. but it you just held the pedal, and hoped something is going to happen.... well...something will.

James K0UA

 

[MHarryE]

Like has been mentioned, keep the radiator and oil cooler clean. A hydro heats the oil a lot more than straight gear transmissions and the oil cooler is there to get rid of that heat. Use lowest gear that will get you the speed you want. You might be able to pull ok in a higher gear but the transmission pressure will be higher = faster wear. Back off on the pedal when the engine pulls down. That's about all there is to it except that the hydro is a piston pump and motor set and piston units thrive on clean oil.

 

[oldnslo]

With an HST, try to avoid sudden directional changes especially when travelling at higher speeds. This sudden change in direction can cause some very intense pressure spikes and also can potentially cavitate/starve the pump for oil for a brief time. This more prevelent in systems with hoses like skid steers but is still some thing to consider.

Also when cold, listen to your tractor. If the HST is screaming at you that means the oil is still cold and you cavitating the unit which results in a premature death. Slow down or let the tractor sit for a few minutes. HST's warm them selves via the charge pump loop.

 

[BeezFun]

Other question, who has experience running hydr. implements from other people/tractors? Won't the oil coming out of it cause problems with the oil of the HST? Surely not everyone knows what oil is in the implement

My neighbor and I share his post pounder, it holds quite a bit of fluid. When I attach it I put the return line into a gallon container and work the cylinder until fluid color changes. Then I add my fluid to my reservoir to top off. When he gets it back he pours the fluid into his reservoir and pumps out mine into the gallon can and gives it to me. Lather, rinse, repeat. He's got a funny looking green tractor that uses a different kind of fluid, even though we're both diligent about changing fluids we felt better not mixing the different kinds of fluids.