BX25D engine brakign vid

[millsan1]

In another thread there was a discussion re: whether or not the new BX series has engine or trans braking.

I am far from an expert and I can only speak to my BX, but the transmission or engine braking works just fine on mine.

This video show me driving my BX25D. I am running at 3,000 RPM, in high gear 2WD. The only thing I do is take my foot off the pedal and machine comes to a rapid stop, I would say with 25 feet.

 

[JOHNTHOMAS]

If it takes 25' to stop when pedal released it is NOT working right. It should stop within a few feet or less. What about in low at a low speed? How short is the stopping distance?

 

[millsan1]

In low gear, or lower speeds, stop is almost instant. I rarely use the brakes themselves, except to hold myself in place. If I just let up on the pedal when working, the stop is abrupt.

I did this demo as a worst case scenario. Full speed, full throttle. 25' is 1 length from about 12 MPH. 25' is a guess on my part.

 

[rjkobbeman]

Mine works about the same. When going backwards then release the pedal, the stop is immediate. When going forward, it seems to slowly slow down. Don't know if this is HST adjustment or pedal adjustment.

I used to use a New Holland. When you released the pedal, it stopped dead in its tracks... and would not move, even if pointed downhill. Wish my BX did that.

 

[s219]

In another thread there was a discussion re: whether or not the new BX series has engine or trans braking.

I am far from an expert and I can only speak to my BX, but the transmission or engine braking works just fine on mine.

This video show me driving my BX25D. I am running at 3,000 RPM, in high gear 2WD. The only thing I do is take my foot off the pedal and machine comes to a rapid stop, I would say with 25 feet.

If you do that on other Kubota's, you would practically get thrown over the steering wheel. 25 ft is not typical, and I think that is what people are complaining about. The higher the gear and speed, the more abrupt and violent it would feel. I know when road transporting my Kubotas in high gear, I have to very gently feather off the pedal before coming to a stop otherwise it's a very abrupt and jerky stop.

The issue isn't really engine braking -- it has to do with how quickly the HST treadle is allowed to return to center by the damper. The resulting braking action is independent of engine RPM for the most part (other than the RPM determined the starting speed of course). It's caused by the HST itself.

Engine braking generally happens when the transmission drives against the engine and the vehicle's motion raises engine RPMs. That can't really happen with an HST setup, it's more of something you get with manual or automatic transmissions. An HST is a separate hydraulic pump arrangement, and it can't really back-load an engine (can certainly forward-load it though).

 

[SLIMSHADIE]

Ive seen numerous posts on this.
Per workshop manual its called Dynamic Braking. There is an adjustable Hst spring.
Turn on engine, full rpms, 2wd and in high range.
On concrtete level ground at full speed, let off and it should stop at 9.8'

I checked mine last fall and it was a little under. Im used to it so I'm happy with it. Any less and I'd be in the bucket.

 

[JOHNTHOMAS]

Many people are/were happy with the abrupt stop in reverse on the BXxx50 series and that's fine but they were/are wrong. Many people will be happy/OK with the rolling stop on the BX25Ds which is also wrong. I wasn't happy with the BX2350 abrupt stop and traded it back to Kubota dealer and rec'd some additional compensation from Kubota. I traded it to a BX2660 and it stopped right in reverse.
I've taken my BX25D back to the dealer and the master mechanic worked on it twice and said no more adjustment available. It's still "not right" but I'll live with it. I'll never say it's right as long as it keeps rolling after the foot pedal is released. What ever the reason and lots of reasons and fixes were given by owners/observers for the BXxx50 series but none of them ever worked to stop the abrupt stop in reverse. Kubota has done something in the BX25D dynamic braking system that has made it wrong. I believe the next series will be fixed on the fix will be done to new BX25Ds with no announcement. If I were buying again I'd refuse the machine until the dynamic braking was fixed/changed. I'm certain all of the BX25Ds on Barlows lot does the same or did a month ago when I took mine in.
What ever the reason or fix, it should immediately stop when the pedal is released abruptly and easing back on the pedal should let it come to a stop based on the amount of let off on the pedal.
My RTV1140 will throw me thru the windshield if I let off abruptly on the foot pedal but will gradually stop with easing off the pedal. That's operating right. This also isn't my first BX25 or even my first Kubota HST in the BX, B or/and L size.

 

[ddb123]

It looks pretty abrupt to me, without being dangerous. My tractor is the same. In lower gear it is a somewhat more violent deceleration, but in higher gear it slows down and stops through about one tractor length. My tractor is also more likely to roll in higher gears, but in Low it stops dead, even on a fairly steep incline.

 

[JOHNTHOMAS]

It looks pretty abrupt to me, without being dangerous. My tractor is the same. In lower gear it is a somewhat more violent deceleration, but in higher gear it slows down and stops through about one tractor length. My tractor is also more likely to roll in higher gears, but in Low it stops dead, even on a fairly steep incline.

Exactly. Yours is working like about all HSTs but the new BX25D is NOT stopping in low gear at low speed like yours. It continues to roll in low gear at low speed and will continue to roll down a slight incline if the brake isn't applied. Mine seems to stop a bit more abrupt in reverse like it should and some times it stops better in forward but often times it keeps rolling which is wrong. Yours is right but this new BX25D isn't right and isn't doing like yours and should..

 

[ddb123]

Exactly. Yours is working like about all HSTs but the new BX25D is NOT stopping in low gear at low speed like yours. It continues to roll in low gear at low speed and will continue to roll down a slight incline if the brake isn't applied. Mine seems to stop a bit more abrupt in reverse like it should and some times it stops better in forward but often times it keeps rolling which is wrong. Yours is right but this new BX25D isn't right and isn't doing like yours and should..

I see, didn't realize that was part of the issue. That would be annoying.