Back to HST problum

[torch]

The transmission has a very significant change between high,med& low it is in either H M L when you shift to any one

Just to clarify: the H M L are mechanical ranges and are actual, physical, gears. They are multipliers for the HST. But within each of those ranges, the pedal position acts like a variable transmission. Tiny press of the pedal = 1st gear, 1/4 pedal = 2nd gear, 1/2 pedal = 3rd gear, 3/4 pedal = 4th gear, full pedal = 5th gear.

Think of it like a hi/lo axle on a truck - there's 1, 2, 3, 4, 5 Low, and 1, 2, 3, 4, 5 High, The HST has <pedal position> Low, <pedal position> Med. and <pedal position> High.

Clear as mud?

 

[ferguson]

Just to clarify: the H M L are mechanical ranges and are actual, physical, gears. They are multipliers for the HST. But within each of those ranges, the pedal position acts like a variable transmission. Tiny press of the pedal = 1st gear, 1/4 pedal = 2nd gear, 1/2 pedal = 3rd gear, 3/4 pedal = 4th gear, full pedal = 5th gear.

Think of it like a hi/lo axle on a truck - there's 1, 2, 3, 4, 5 Low, and 1, 2, 3, 4, 5 High, The HST has <pedal position> Low, <pedal position> Med. and <pedal position> High.

Clear as mud?

Not goin to get to work on it until tomorrow

 

[RCW]

Earlier you said to had the pedal pushed all the way down, or similar.

What torch is trying to say is that when you "mash" the pedal all the way down on an HST tractor, you can have the opposite effect as your car or truck.

Mashing pedal down fully takes it to a higher gear ratio = less/no power to wheels.

Let off/ease off the pedal = more power to wheels.

 

[Dustyx2]

Not goin to get to work on it until tomorrow

Take this guys advice and do some experimenting with the pedal position and resulting power output.
It's common for a new to hydro transmission operator to have the accelerator pedal expectation of performance when the reality is just the opposite. That was me when I first got my little BX.
You'll also find that hydrostatics aren't great with ground engaging tools due to their inherent inefficiency's. It's not going to perform those tasks like your TO will. Hydrostatics excell at tasks such as loader work where you are doing lots of direction changes and fine movement.

 

[ferguson]

Take this guys advice and do some experimenting with the pedal position and resulting power output.
It's common for a new to hydro transmission operator to have the accelerator pedal expectation of performance when the reality is just the opposite. That was me when I first got my little BX.
You'll also find that hydrostatics aren't great with ground engaging tools due to their inherent inefficiency's. It's not going to perform those tasks like your TO will. Hydrostatics excell at tasks such as loader work where you are doing lots of direction changes and fine movement.

will do

 

[ferguson]

Just to clarify: the H M L are mechanical ranges and are actual, physical, gears. They are multipliers for the HST. But within each of those ranges, the pedal position acts like a variable transmission. Tiny press of the pedal = 1st gear, 1/4 pedal = 2nd gear, 1/2 pedal = 3rd gear, 3/4 pedal = 4th gear, full pedal = 5th gear.

Think of it like a hi/lo axle on a truck - there's 1, 2, 3, 4, 5 Low, and 1, 2, 3, 4, 5 High, The HST has <pedal position> Low, <pedal position> Med. and <pedal position> High.

Clear as mud?

OK did the jack up test / all 3 ranges /2w &4w / NO power loss / Pedal position tractor has a cruise control leaver which holdes the pedal in any position from just enough to move the tractor to full pedal/ tried it in 6 spots from just engaged to move to full pedal it is better in any positan then fully engaged / also tried on the road going up a hill/Its better backed off the peddle but not wow better / Pedal adjustment is !00% correct according to book / That being said oil flow restriction but WHERE?? /going to drain oil tomorro & pull filters /only 20 hr on oil & filters now /also problum started befor oil & filter change

 

[ferguson]

Just to clarify: the H M L are mechanical ranges and are actual, physical, gears. They are multipliers for the HST. But within each of those ranges, the pedal position acts like a variable transmission. Tiny press of the pedal = 1st gear, 1/4 pedal = 2nd gear, 1/2 pedal = 3rd gear, 3/4 pedal = 4th gear, full pedal = 5th gear.

Think of it like a hi/lo axle on a truck - there's 1, 2, 3, 4, 5 Low, and 1, 2, 3, 4, 5 High, The HST has <pedal position> Low, <pedal position> Med. and <pedal position> High.

Clear as mud?

Also set up dial indactor on all hubs check end play & runout / every thing tight

 

[RCW]

Ferguson- - okay.

PLEASE try the tractor without jamming the pedal to the bottom of it’s travel on the ground.

No cruise control! Don’t change anymore oils or filters!

Just go easy with the the pedal, with plenty of throttle.

Not more than quarter to half of the pedal’s travel.

Make throttle more than half of wide-open.

I used to put a wood block under my kid’s gas pedal so they couldn’t go too fast. Think the same way with your pedal…..

@Fordtech86 - are you satisfied something isn’t binding, or is there something else he can do to eliminate that possibility?

 

[Fordtech86]

Ferguson- - okay.

PLEASE try the tractor without jamming the pedal to the bottom of it’s travel on the ground.

No cruise control! Don’t change anymore oils or filters!

Just go easy with the the pedal, with plenty of throttle.

Not more than quarter to half of the pedal’s travel.

Make throttle more than half of wide-open.

I used to put a wood block under my kid’s gas pedal so they couldn’t go too fast. Think the same way with your pedal…..

@Fordtech85 - are you satisfied something isn’t binding, or is there something else he can do to eliminate that possibility?

So I have 0 hst experience, but
understand what y’all are talking about mashing the pedal down. When this happens does it actually drag the engine down or does it just make the hst go into a relief. Still working on my Kubota GED from OTT, but from what I think I’ve read is they just start whining more then usual and just lose acceleration.

Following along here the OPs tractor when it does this is bogging the engine and he has mentioned when it happens it also blows black smoke, that tells me it’s getting plenty of fuel (which fuel system had been beat to death) and its got no problem burning fuel (compression good, which has also been covered).

I don’t have any experience working on Kubotas so I don’t know where to point the OP exactly.

 

[Dieseldonato]

Ita perfectly normal to have an engine bog down when you flatten the hst, pedal when in hi or medium gear. Especially when doing ground engaging work with a 30 hp tractor. Spinning a mower without cutting is also a worthless test of pto or engine power. The hardest part it starting the mower. Takes little effort to keep it at speed. It's also typical not to be able to go up a steep hill with the hst mashed to the floor in high gear. I have ran hydro tractors from 12 to 65hp and up a steep hill full bore wasn't/isn't possible. Also if you just mashing the pedal down the hydro is more then happy to cooperate, but often times the engine just can't keep up with such a high demand all at once. This is akin to a gear tractor and side stepping the clutch in high gear. You'll be lucky if it doesn't stall out.
My advice is there's nothing wrong with your tractor you just need to get used to how it works. If you really think there is an issue with engine out put or hst function they can both be easily tested. Engine via a pto dyno, and the hst should be able to be tested as well. Although I think that would need a dealer to find out how to test it. I would think a pressure test would suffice.

 

[Fordtech86]

Ita perfectly normal to have an engine bog down when you flatten the hst, pedal when in hi or medium gear. Especially when doing ground engaging work with a 30 hp tractor. Spinning a mower without cutting is also a worthless test of pto or engine power. The hardest part it starting the mower. Takes little effort to keep it at speed. It's also typical not to be able to go up a steep hill with the hst mashed to the floor in high gear. I have ran hydro tractors from 12 to 65hp and up a steep hill full bore wasn't/isn't possible. Also if you just mashing the pedal down the hydro is more then happy to cooperate, but often times the engine just can't keep up with such a high demand all at once. This is akin to a gear tractor and side stepping the clutch in high gear. You'll be lucky if it doesn't stall out.
My advice is there's nothing wrong with your tractor you just need to get used to how it works. If you really think there is an issue with engine out put or hst function they can both be easily tested. Engine via a pto dyno, and the hst should be able to be tested as well. Although I think that would need a dealer to find out how to test it. I would think a pressure test would suffice.

not trying to argue you at all, but I believe it’s having issues even in low gear pulling a ground engaging implement. It has been a very difficult story to follow, a video of what all was happening when the concern exists might be best to discern from normal operation or a problem exists. Sounds like OP has other tractor(s) on the same property that don’t exhibit the same concern (be it they may be of a different breed).

 

[Grassandstuff]

Had nearly same problem with my mx5100 hst recently. I pull a 15 ft bat wing woods finishing mower, 130 acres of an old golf course. Over a week or 2 started getting sluggish, then didn't even go up the small hill greens in mid range without bogging. Over thought everything to I went back and changed fuel filter, snapped back to life immediately. Even though it looked clean, and the fuel pump was pumping great though it, under full load the amount needed for injectors and to recirculate was more than the filter could send. I told my neighbor it was impossible, guess who had to eat crow. I thought it was definitely engine or pump related. 51 hp is barely enough for the 15 foot and 6 inch grass. Not sure you're hp but if you're pulling anything 24 ' wide, you better have 150 hp.

 

[torch]

That being said oil flow restriction but WHERE?? /going to drain oil tomorro & pull filters /only 20 hr on oil & filters now /also problum started befor oil & filter change

On my tractor, there's 3 filters -- one coarse mesh screen that has nothing to do with the HST, it's in the suction to the other hydraulics. A disposable spin on bypass filter that won't restrict the flow to the HST. And finally a second, fine mesh, screen that feeds the charge pump for the HST. This would be the only one that could restrict flow to the HST. (but that shouldn't bog the engine down -- see below). Check your manual to confirm if this is also true for your tractor.

I am still curious what fluid you put in the tractor? Did the label state it meets the requirements of Kubota UDT? Or was it generic hydraulic fluid? It is interesting that the problem is worst when "cold". It's not like we are in the middle of winter right now.

Do you have a way to measure the engine RPM? Are we sure that you are actually at full throttle?

So I have 0 hst experience, but
understand what y’all are talking about mashing the pedal down. When this happens does it actually drag the engine down or does it just make the hst go into a relief.

It drags the engine down.

The pedal actually controls the position of the swash plate in the variable displacement HST pump. The further the pedal is pushed, the greater the deflection of the swash plate and therefore the pump's displacement increases so the flow rate increases to the fixed displacement hydraulic motor. The higher the flow, the faster the hydraulic motor spins. If there is no load.

Nothing comes for free. Increasing the pump output increases the load on the engine. The pedal does not do anything with the throttle or fuel. If the pump puts a greater load on the engine than the engine can deliver, such as going uphill or dragging a ground-engaging implement, the engine will bog down. Also, the available engine power will be reduced by powering PTO or hydraulic implements. So while the tractor may happily scoot up a given hill with nothing else attached, it could have trouble on the exact same hill when powering a mower, etc.

 

[Fordtech86]

On my tractor, there's 3 filters -- one coarse mesh screen that has nothing to do with the HST, it's in the suction to the other hydraulics. A disposable spin on bypass filter that won't restrict the flow to the HST. And finally a second, fine mesh, screen that feeds the charge pump for the HST. This would be the only one that could restrict flow to the HST. (but that shouldn't bog the engine down -- see below). Check your manual to confirm if this is also true for your tractor.

I am still curious what fluid you put in the tractor? Did the label state it meets the requirements of Kubota UDT? Or was it generic hydraulic fluid? It is interesting that the problem is worst when "cold". It's not like we are in the middle of winter right now.

Do you have a way to measure the engine RPM? Are we sure that you are actually at full throttle?



It drags the engine down.

The pedal actually controls the position of the swash plate in the variable displacement HST pump. The further the pedal is pushed, the greater the deflection of the swash plate and therefore the pump's displacement increases so the flow rate increases to the fixed displacement hydraulic motor. The higher the flow, the faster the hydraulic motor spins. If there is no load.

Nothing comes for free. Increasing the pump output increases the load on the engine. The pedal does not do anything with the throttle or fuel. If the pump puts a greater load on the engine than the engine can deliver, such as going uphill or dragging a ground-engaging implement, the engine will bog down. Also, the available engine power will be reduced by powering PTO or hydraulic implements. So while the tractor may happily scoot up a given hill with nothing else attached, it could have trouble on the exact same hill when powering a mower, etc.

i do understand that, and I may have missed where the OP has said they are mashing the hst pedal to the floor when the concern exists, that seems to be have been implied

 

[torch]

i do understand that, and I may have missed where the OP has said they are mashing the hst pedal to the floor when the concern exists, that seems to be have been implied

Ferguson never used the word "mash", that was someone else, but the amount of pedal travel came into the discussion when he noted the tractor would spin the tires when nosed up against a tree, but bog down traveling up a slight hill, even in low range.

 

[GreensvilleJay]

OK, Now I'm totally confused... If you read one way it's NOT and engine problem, read another, it's NOT a drivetrain problem, if both are true , it kanida leas to 'operator error' ??
OP says he runs a 24' batwing mower and TractorData says he has a 32HP tractor(L3130HST). Another site says he has 24 PTO HP. A quiklook for those mowers,they all need 100+HP !!
Maybe it's time for a 'recap' ? Start off with list of equipment,problem, things done ?

 

[ferguson]

Had nearly same problem with my mx5100 hst recently. I pull a 15 ft bat wing woods finishing mower, 130 acres of an old golf course. Over a week or 2 started getting sluggish, then didn't even go up the small hill greens in mid range without bogging. Over thought everything to I went back and changed fuel filter, snapped back to life immediately. Even though it looked clean, and the fuel pump was pumping great though it, under full load the amount needed for injectors and to recirculate was more than the filter could send. I told my neighbor it was impossible, guess who had to eat crow. I thought it was definitely engine or pump related. 51 hp is barely enough for the 15 foot and 6 inch grass. Not sure you're hp but if you're pulling anything 24 ' wide, you better have 150 hp.

Just hooked up to 24' mower to test engine while not travling

 

[ferguson]

OK, Now I'm totally confused... If you read one way it's NOT and engine problem, read another, it's NOT a drivetrain problem, if both are true , it kanida leas to 'operator error' ??
OP says he runs a 24' batwing mower and TractorData says he has a 32HP tractor(L3130HST). Another site says he has 24 PTO HP. A quiklook for those mowers,they all need 100+HP !!
Maybe it's time for a 'recap' ? Start off with list of equipment,problem, things done ?

Mower hook up was just test eng, through the P T O with out travling

 

[RCW]

Ferguson never used the word "mash", that was someone else, but the amount of pedal travel came into the discussion when he noted the tractor would spin the tires when nosed up against a tree, but bog down traveling up a slight hill, even in low range.

Torch - - I used "mash," as in mash the gas.

I also caught the comment about it spinning wheels when pushed against a tree. RPM's come back if let off pedal.....I was focusing on that. Maybe too much.

Yes pedal all the way down travling / just abit pushing against the tree / when travling if i let up on the peddle just a bit RPM cum pack up / filters oil less then 20 hr old / there are apparently high psi relifes valves inside ?????? maybe

 

[ferguson]

On my tractor, there's 3 filters -- one coarse mesh screen that has nothing to do with the HST, it's in the suction to the other hydraulics. A disposable spin on bypass filter that won't restrict the flow to the HST. And finally a second, fine mesh, screen that feeds the charge pump for the HST. This would be the only one that could restrict flow to the HST. (but that shouldn't bog the engine down -- see below). Check your manual to confirm if this is also true for your tractor.

I am still curious what fluid you put in the tractor? Did the label state it meets the requirements of Kubota UDT? Or was it generic hydraulic fluid? It is interesting that the problem is worst when "cold". It's not like we are in the middle of winter right now.

Do you have a way to measure the engine RPM? Are we sure that you are actually at full throttle?



It drags the engine down.

The pedal actually controls the position of the swash plate in the variable displacement HST pump. The further the pedal is pushed, the greater the deflection of the swash plate and therefore the pump's displacement increases so the flow rate increases to the fixed displacement hydraulic motor. The higher the flow, the faster the hydraulic motor spins. If there is no load.

Nothing comes for free. Increasing the pump output increases the load on the engine. The pedal does not do anything with the throttle or fuel. If the pump puts a greater load on the engine than the engine can deliver, such as going uphill or dragging a ground-engaging implement, the engine will bog down. Also, the available engine power will be reduced by powering PTO or hydraulic implements. So while the tractor may happily scoot up a given hill with nothing else attached, it could have trouble on the exact same hill when powering a mower, etc.

Used tracotr supply UDT fluid on lable meets Kubota Asked 4 other kubota owners in aria about this fluid all use it / RECAP problum has steadily increased /travilng on road small incling eng. bogs down to almost a stall out / Started befor fluid & filter change / every body said fuel delivery problum / went through fuel system 3 times /tank out , all fuel lines changed , fuel pump changed , new injectors . PSI test system , injector cleaner added , compression test , air intake system dissembled & ckecked / AT THIS POINT I HAVE RULED OUT A ENGINE There nothing wrong with it / This is why im back a Trasn/HST problum / Did jack up test all ranges H M L no problum / while i had it jacked up put dial indicator on all hubs check end play & run out all tight / next is to check internal screens for blockage / also roll free in neutral / will roll a bit idling in gear on hill / push test against tree H & M range will stall eng. Low will break traction / Backing off peddle seems to help ????? mayde /peddle adj. correct as per book / big mower was just a test on eng, without trens & HST //// THIS is every thing AGEN THANKS TO ALL FOR YOUR INPUT IN HELPING ME WITH THIS ISUE