Runaway Tractor (not runaway diesel)

[Kamaluhiafarm]

BX2680 with mid mower. My property is fairly steep, requires 4WD tractor, hasn’t been an issue until few days ago. Driving downhill, it was as if the transmission was disconnected, and the tractor just free wheeled down this steep hill, brake did nothing either; I was along for a sled ride that was more exciting than I cared.

I’m new to tractor owner/operator, there’s always the possibility of pilot error. I’m not doing anything different than I have been doing, what might cause this runaway behavior?

 

[Treckerzeug]

Hello,

If the 4wd was disengaged, the rear tyres have not much weight, so no adherence, no braking force to be transmitted as the rear wheels are just hopping without resistance,
I would recommend to check if the 4wd lever is on engaged or on released...
Take care, goid luck!

 

[TX Chris]

Do you know if the rear tires were skidding (locked up) with no traction or were you just free-wheeling down the hill with no resistence from the brakes or transmission? Two very different issues depending on which it was.

 

[Kamaluhiafarm]

Nailed it! I had not changed the front drive lever yet it was disengaged. Consistent with your diagnosis, there are skid marks down the hill, assuming from rear wheels.

Rear tires are filled with water, and 300lb ballast box on rear, I would have thought there was enough rear weight. Surprising that front drive would have that large an impact on braking, also consistent with climbing uphill felt it slip.

Adding “front drive - engaged“ to my pre-start checklist, thank you for your help.

 

[Kamaluhiafarm]

Do you know if the rear tires were skidding (locked up) with no traction or were you just free-wheeling down the hill with no resistence from the brakes or transmission? Two very different issues depending on which it was.

I briefly was able to see the rear wheels, and they appeared to be turning, there were wide skid marks though all the way down the hill. It felt as if the wheels were free wheeling, and definitely no braking action. Your latter description more closely matches my experience.

Based on first reply, I did find front drive was disengaged.

 

[Bmyers]

When dealing with hills, use a lot of caution. Rops need to be up and seatbelt on. The 4wd feature will help with keeping the tractor from going out of control.

here are some videos that you may find useful as a new tractor own dealing with hills.

 

[Bmyers]

One more video for you

 

[Kamaluhiafarm]

Thanks for the videos, not familiar with Tractor Mike. I got comfortable operating on steep hills fairly quickly, and never sideways! Seatbelt and ROPS always.

 

[Kamaluhiafarm]

Additional info: I found this morning, hydraulic fluid is low. Related?

 

[Kamaluhiafarm]

Additional info: I found this morning, hydraulic fluid is low. Related?

Just below dipstick, could still see oil

 

[old and tired]

Is this gear or HST? Just to make sure... Yes, the rear tires will loose traction going down hill in 2 wheel drive... If you have LOTS of weight on the three point hitch, you might have enough traction. With 4x4 on, the rear brakes transfer traction to the front tires....

 

[Kamaluhiafarm]

Transmission fluid, behind the seat

 

[JimmyJazz]

I had a similar experience recently due to a blown hydraulic line. Could have resulted in serious injury . Terrifying. The kind of thing that happened so fast that the fear came later and still persists. I am still considering hiring someone to cut my grass and selling my tractor. Once bitten twice shy I suppose.

 

[skeets]

If you happen to bump it out of gear things get real interesting too,, and if the grass was a tad damp,,,, and not in 4wd it will slip and the tires will turn but not fast enough to keep up, and slaming onthe breaks will leave marks on the grass and in your shorts ,, just sayin,, dont ask

 

[NCL4701]

I have found with one particular jacket it’s easy to accidentally knock mine into neutral and the HST transmission that usually takes care of most of the braking just doesn’t brake so well in neutral. Easy to exceed rated top speed quickly when tractor is oriented correctly on a slope and transmission is out of the equation. Dropping the loader and box scrape does slow it down if the brakes aren’t helping but leaves some repair work to be done. Don’t wear that jacket on the tractor these days. And I don’t like being on slopes without the loader running low or a rear implement that gives me the option to drop anchor.

 

[hope to float]

Another thing that can happen when you lose traction is one wheel spinning forward and the other backwards. Sometimes what is needed is more throttle.
Had a tractor pop out of gear pulling a few ton of peat down a gravel mountain road once. Braking was the worst thing I could do with all that weight behind a 2 wheel drive tractor but I managed to kick the brakes for a split second to crash it into top gear. Once it was in gear I pulled the "pull to stop" button and had a little walk around and a smoke after it braked itself, then climbed back in and carried on. This time I kept it in gear with one hand

 

[Kamaluhiafarm]

After speaking with my dealer sales person, I have a theory with nothing to substantiate it: low on hydraulic fluid (about 1/2qt, no idea where it went), going down steep hill, perhaps the hydraulic pickup unported? After I got to the bottom of the hill, the transmission began working again. Today, topped off fluid and everything is fine. Really wish I could come up with reason why it happened and how to avoid in future; don’t like these intermittent problems.

Thank you to everyone with suggestions, and sharing their experience. Kubota dealer issued TSR(?), asking if others have had similar issues, maybe it’s a known issue.

 

[bbxlr8]

I know this is a few weeks old but FWIW: your description fits exactly what happens on my old 2WD HST turf tire tractor w/60"mmm when cutting and losing traction. I am on a ridge and the majority of my property is sloped. It is VERY unnerving and I have learned to anticipate steer into it and keep the pedal down to control when it catches traction again. Instinct is to let up/brake which can swing you around.

Did you ever hear anything back from the dealer otherwise?

 

[Kamaluhiafarm]

Never did hear anything back from dealer, topped off hydraulic fluid by adding approx 1/2qt, hasn't happened since but it was very intermittent originally. Makes me cringe every time I think of some of the more tenuous situations I've had it in prior had this happened then.

 

[RCW]

I seriously doubt your 16 ounces of fluid had anything to do with it.

Your tractor takes a little more than 3 gallons of hydraulic fluid.

You lost traction with the rear tires, because you did not have 4wd engaged. Hawaii is a tropical climate, so things can bet wet or damp.

I've had similar rides with all my mowing tractors here, as it's steep too.

I know to put my Kubota in 4WD...usually.

Had a rented plate compactor hanging off the loader couple years ago in 2WD....was an interesting ride for 20 feet, and I knew better...it should have been in 4WD.