Any other Kubota's power steering "hit a stop" for a moment?

[kcender]

I have 300 hours on my 2010 Grand L 3240 and have noticed this bump every now and then since it was new.It usually occurs in the transition of going forwards after backing up, like was mentioned.I run the tractor at around 2000rpm for general FEL work.It bothered me at first but I was waiting to see if it got worse before contacting the dealer.It didn't and I am glad to know it is normal for this tractor and many others.

 

[oldnslo]

Does the "L" series Bota's have a stand alone sterring pump or do they have a priority flow system that gets the oil from the main system pump?

If priority system what you are experiencing is the response time of the valve. Depending on how this valve is made it may provide a "Constant" flow to the steering circuit or it may be an "On Demand" system.

"Constant" flow is what the BX Series use in that there is always flow going to steering, charge, etc.

"On Demand" systems are just that. when there is no demand for steering all of the flow is being diverted to the remote valves/implement circuit. This style of system is more common on larger tractors. The "On Demand" is also more likely to exihibit the pause in the steering function.

Example: Large 4WD articulated steer tractors may require up to 50 - 60 GPM for an emergency steer so this flow is taken from the implement circuit instead of having it's own pump. This is done to save HP loss and 99% of the time the operator will never know what is happening.

Roy

 

[Bird]

Yep, nothing unusual about that little steering anomaly. Here's just one of several threads from over 10 years ago: B2710 Steering Problems and you can got to the search function and enter "B2710 + steering" and find some more.

 

[beppington]

Just emailed my dealer on this again, since I haven't heard back yet.

Also ... The spec sheet for my Grand L3940 says, under "Hydraulic":

Implement pump (GPM): 9.8
Power steering pump (GPM): 4.9
Total hydraulic flow (GPM): 14.7

Not to say it doesn't have such a thing, but there's no mention of a "priority flow system".

 

[beppington]

Dealer responded a few minutes ago: "... I talked to engineers at Kubota and didn't ring any bells with them. Sug: Just keep using it, and hopefully it will get worse to the point of all the time. Then we can troubleshoot it and get it fixed for you under warranty. Note: Pay attn. to where on the steering it does it (ie: always turning to the left, about 30 degrees, or once I have made one full revolution to the right, etc) Wish I had more but that's all we got right now."

 

[SPYDERLK]

Still no response from my dealer yet; Still prob due to holidays.

I did notice today, though, that the steering "bump" seemed to occur most often while turning while going forward just after having been backing up. Like the transition from backing to forward is a little too much for the tractor's hydraulics. I foresee this getting to where I can actually make it happen.

Now your worrying me. My 1500 had the cradle bearing break in its HST. The locomoting ability showed trouble and got so it would hardly move. However, during its decline the tractor exhibited an occasional kick at the steering wheel while in use ... and it would happen in conjunction with or following other hydraulic loads. My BX had never done anything like it. I definitely had a hydraulic problem due to feedback effects from a broken part. I dont think you have a broken part, but remembering that bump/kick in mine gives me a bad gut reaction based on the connection you describe to other actions. Its probably just your proportioning valve. Id have it looked into if only to set your mind at rest.
larry

 

[Happyman]

My 2007 L3940 does the same thing but only when I am pushing the FEL to capacity. Like removing a pallet of fertilizer from a trailer and the load is so heavy I have to run the rpm's up to about 2700 to get enough lift. While backing out and turning I get that "bump" in the steering. I have found that if I drop in the 4WD the steering works just fine. Kind of odd, but happens so little that I don't worry about it.

 

[oldnslo]

Just emailed my dealer on this again, since I haven't heard back yet.

Also ... The spec sheet for my Grand L3940 says, under "Hydraulic":

Implement pump (GPM): 9.8
Power steering pump (GPM): 4.9
Total hydraulic flow (GPM): 14.7

Not to say it doesn't have such a thing, but there's no mention of a "priority flow system".

If this is truely a seperate steering pump then it should be hard to turn all the time instead of just a small bump.

Steering units are motors that when turned faster than the oil supply to them turn into pumps. What you are feeling is the transition from motor to pump. If the "Supply" pump is to small your steering would always be hard past a given steering wheel RPM. If it is just a bump this indications a response time of a priority valve.

If you add up the 9.8 & 4.9 it = 14.7 In my feeble mind if it was two seperate pumps would it be considered "total hyd flow"

Does anyone has a hydraulic schematic of the "L" series they can post? This might answer some questions or possibly create a bunch more.

I can't remember the model of IH from years ago but I do remember the priority valve hanging up in it and it would make steering very hard.

Roy

 

[DDT]

The other day I was pushing snow and mine locked up to about 3 seconds, thank god I was not close to any one or thing ( building,car ect). I let my dealer know to see if there is some thing we can do. He told me there was no other complaints on Kubota dealer web site??? Is any one eles talking to there dealer?

 

[blueone]

Was looking back at some threads and was wondering if this issue has been resolved or caused any failures for anyone?