Kubota L3540 stuck in Reverse

[PJA]

Hi Everyone, New to the forum. I have an L 3540 Kubota Tractor used for bush hoggin. worked fine. Had someone fix the tire on the rear of the bush hog, add coolant for the AC and they hosed off the radiator. They started up the tractor (not sure how comfortable they were with this model of tractor/?jamming controls??) and suddenly it would only go in reverse , regardless of the pedal position. I also can't get it to brake unless I put it in neutral. Any thoughts? Hoping for a simple fix. Any advice much appreciated.

 

[Jchonline]

HST correct?
From what you describe it sounds like it is just staying in reverse...which on HST this is controlled by the pedal. So I wonder if you are missing a linkage pin or something. Others may know more.

Kubota L3540HST-3 (Hydrostatic Transmission / Rops / 2010) Parts Diagrams (messicks.com)

 

[PJA]

HST correct?
From what you describe it sounds like it is just staying in reverse...which on HST this is controlled by the pedal. So I wonder if you are missing a linkage pin or something. Others may know more.

Kubota L3540HST-3 (Hydrostatic Transmission / Rops / 2010) Parts Diagrams (messicks.com)

Sorry for the delayed reply. Yes. HST. Reading up on this now. New to tractors. Thank you!

 

[D2Cat]

Sounds like you have left a wrench or socket under the pedal and it can't return to neutral!

 

[ruger1980]

You say it only travels in reverse.
Does it return to neutral and stop traveling when the pedal is in the neutral position?
What does the tractor do when you push the pedal forward and does it push forward at all?
It does sound like a linkage related issue but the parts breakdown shows 2 solenoids on the servo regulator so it may be possible they are drive enable solenoids but without a service manual I am only guessing.
Make sure the wires are connected to the solenoids when you are down checking the linkage.

 

[PJA]

When I put it in M the tractor keeps moving in reverse even when my foot is totally off of the pedal.

It stops traveling in reverse only when I put it in Neutral. The brakes don't work at all.

If I put the pedal down in forward it also continues to travel in reverse. Thanks for your help, everyone!

 

[RichHuey]

When I put it in M the tractor keeps moving in reverse even when my foot is totally off of the pedal.

It stops traveling in reverse only when I put it in Neutral. The brakes don't work at all.

If I put the pedal down in forward it also continues to travel in reverse. Thanks for your help, everyone!

I am having this exact problem!
Please tell me what had to be done to fix it.

Neutral pedal and I am going backwards, and there is no stopping it. Breaks are worthless
What I have found is at about 1/2 pedal forward it will stop. Full pedal forward and it stands still.

I have replaced the pedal sensor with no change.

The pedal moves freely.

I hope you got yours fixed. I especially hope you can tell me what needs to be done.

Thanks

Rich

 

[mikester]

Check your linkages and look for missing springs etc

 

[RichHuey]

Check your linkages and look for missing springs etc

Everything looks correct.

There really isn't any linkage, the pedal drives a potentiometer.

 

[mikester]

If it's servo drive get some contact cleaner and clean all the connectors from the pedal down to the fwd/rev servos. Make sure every connector is seated properly.

I posted here on something similar that happened to me this winter

Kubota L4701 Sometimes Stalls When Moving Forward with HST Pedal

This winter I've been having a problem with the tractor where it starts fine, and then when I press the HST pedal to move forward it stalls. If I leave off the pedal quickly it will not stall and RPMs will come back up. Interestingly, when pressing the pedal for reverse it does not stall. Is...

www.tractorbynet.com

I don't know your machine but on mine the servos are a PITA to reach without extra long forcepts.

Post again with your results.

 

[RichHuey]

If it's servo drive get some contact cleaner and clean all the connectors from the pedal down to the fwd/rev servos. Make sure every connector is seated properly.

I posted here on something similar that happened to me this winter

Kubota L4701 Sometimes Stalls When Moving Forward with HST Pedal

This winter I've been having a problem with the tractor where it starts fine, and then when I press the HST pedal to move forward it stalls. If I leave off the pedal quickly it will not stall and RPMs will come back up. Interestingly, when pressing the pedal for reverse it does not stall. Is...

www.tractorbynet.com

I don't know your machine but on mine the servos are a PITA to reach without extra long forcepts.

Post again with your results.

I have started replacing parts, blindly hoping for a positive outcome

New pedal potentiometer
Lower pressure/check valve
Lower HST valve

All these swap outs resulted in no change to the symptoms

I am working on replacing the upper pressure / check valve, but its fitting is rusted and is not being friendly.

Any advice on other parts to swap out would be greatly appreciated.

Thanks

Rich

 

[ruger1980]

First thing is to stop replacing parts. Have you downloaded the WSM from Kubotabooks.com? If not please do so.

If I were diagnosing this issue the first thing I would do is disconnect the HST proportional solenoids to determine if the fault is electrical or within the HST unit. If within the HST the next thing I would do is remove both proportional solenoids, inspect the seals and swap them to see if the complaint moves.

 

[RichHuey]

First thing is to stop replacing parts. Have you downloaded the WSM from Kubotabooks.com? If not please do so.

If I were diagnosing this issue the first thing I would do is disconnect the HST proportional solenoids to determine if the fault is electrical or within the HST unit. If within the HST the next thing I would do is remove both proportional solenoids, inspect the seals and swap them to see if the complaint moves.

Which part is the proportional solenoids?
TD170-59310??

I replaced one those, hard to get to the second....

 

[ruger1980]

Yes it appears that is the pn. Have you downloaded the WSM for your machine? If not please do so.
Do not replace parts. Disconnect the electrical connectors at the solenoids and see if the issue still occurs. It may create a fault code(s) but it will determine of the issue is electrical or within the HST. You will have no control via the pedal so make sure you are in a safe area where nothing is in the way..