Under most circumstances the air can be bled out of the system by activating each function to the stops (over relief) for a few seconds. There are some machines and components of some machines that require special bleeding procedures but for the most part the above will work with pretty much everything. HST sytems are different, operate hydro full fwd and rev with range selector in neutral (wheels of the ground if that option is not available) then operate gently full fwd and rev before putting any major load on it. I think the loader pause may be due to the number of operations the valve is performing in the scenerio reported. Somewhat like the shift from 4th to 5th in GST tractors has alot longer pause do to the fact that not only is the valve shifting the trans gears it's also shifting from low to high range at the same time. As far as an "unmessy" non time consuming procedure for bleeding the ps on effected units there probably is'nt one. I think cracking the inlet line to the ps unit itself would be the best way to do it.
Power Steering Problem Not Solved
- Thread starter Alan L.
- Start date
- Views: 23032
ronjhall
Super Star Member
Alan
Had a visit from <font color=orange>Kubota </font color=orange>Rep. last week. After running tractor for about ½ hour he was able to detect problem with powersteering. He was glad that I made my tractor available for him to use at my place to find problem. I don't have to cut backyard lawn. He did it. He was going to California for a few days and was going to go over problem with <font color=orange> Kubota </font color=orange> engineers. Should be getting back with a plan to repair my tractor this week. He is not sure why problem is happening, but it may be cavitations. Will report back as soon as a fix has been found.
Had a visit from <font color=orange>Kubota </font color=orange>Rep. last week. After running tractor for about ½ hour he was able to detect problem with powersteering. He was glad that I made my tractor available for him to use at my place to find problem. I don't have to cut backyard lawn. He did it. He was going to California for a few days and was going to go over problem with <font color=orange> Kubota </font color=orange> engineers. Should be getting back with a plan to repair my tractor this week. He is not sure why problem is happening, but it may be cavitations. Will report back as soon as a fix has been found.
toddler
Gold Member
- Joined
- Jan 26, 2001
- Messages
- 407
- Location
- North Carolina, USA
- Tractor
- Previously: Kubota B2710. Now Deere 3520
Finally some progress. Hope they can find an answer for you after all the headaches this has caused you.
Todd
Todd
Anonymous Poster
Epic Contributor
- Joined
- Sep 27, 2005
- Messages
- 29,678
Hopefully they will figure something out. Please post the results here.
Thanks,
greg
Thanks,
greg
ronjhall
Super Star Member
Alan
Good news. <font color=orange>Kubota </font color=orange>has come up with a fix for our Power Steering problems./w3tcompact/icons/smile.gif Dealer called today to tell me that he has ordered some parts that will be install by the Field Rep. They should be installing these parts in the next couple of weeks. They also plan on doing some test to verify repair. Will report back with results of changes.
It sure has taken a long time to get results from our complaints.
Newer models of 2710 & 2910 may already have these changes.
I would give Terence Chris at <font color=orange>Kubota </font color=orange>a call. He should be able to get your Feild Rep. and dealer the information needed to repair your tractor.
Good news. <font color=orange>Kubota </font color=orange>has come up with a fix for our Power Steering problems./w3tcompact/icons/smile.gif Dealer called today to tell me that he has ordered some parts that will be install by the Field Rep. They should be installing these parts in the next couple of weeks. They also plan on doing some test to verify repair. Will report back with results of changes.
It sure has taken a long time to get results from our complaints.
Newer models of 2710 & 2910 may already have these changes.
I would give Terence Chris at <font color=orange>Kubota </font color=orange>a call. He should be able to get your Feild Rep. and dealer the information needed to repair your tractor.
Anonymous Poster
Epic Contributor
- Joined
- Sep 27, 2005
- Messages
- 29,678
Alan,
I am a reliability specialis and this is the kind of problem I work on every day. Here are some thoughts:
The system has a pressure relief valve that opens if pressure is too high. If this is sticky you could have implement bouncing causing some problems.
Some systems also have thermal relief valves that open if the oil temp gets too high. To me, 210 sounds high. This is some good information to get from Kubota. Try to get a spec for maximum alowable oil temp. I would like to see gear box oil temperatures below 180 F.
Keep in mind two thoughts:
1. Water boils at 212F at atmospheric pressure. Steam is compressible, so it does not work well in a hydraulic system. A very small droplet of water can flash to a big steam pocket that could cause this problem.
2. Lowering the pressure on the water, or oil for that matter, also lowers the boiling point. The pump suction has a lower pressure than atmosphere. Actual pressure will depend upon the size of the fluid lines, restrictive effects of fittings and bends, and will be lowest at inlet to the pump mechanism. Flashing in your pump inlet could cause loss of pressure and will definitely reduce equipment life. Oil flashes easier at higher temperatures.
Some things you can do:
1. Call the oil manufacturer and ask to talk to an application engineeer. Inquire about the maximum operating temperature for the oil.
2. Consider changing brands of oil. Buy quality. Kubota UDT may not be. Yes it is expensive. Are $57 bolts quality or just expensive?
3. Send out two samples of oil for analysis. One sample of new, fresh oil, one from your tractor. Compare. Ask for moisture content, which will be parts per million (ppm) or possibly percent.
4. Consider installing an oil cooler in front of your radiator. This can be tricky if you live up north, because you can cool the oil too much in cold months. On a car, you always install the trans cooler such that the oil passes through the cooler and cools off, then passes through the radiator exchanger. The oil heats back up to your coolant temperature. This trick also adds radiator cooling capacity.
John Drre 5400 series have a trans oil cooler in front of the radiator.
At our plant we buy muilti-million dollar machines, spend months finding and fixing these kind of problems, then have the equipment manufacturers asking us "Have ya'll had that xxx problem happen any more? You have quit asking questions about that system?" My reply: "Strange, come to think of it, no we have not seen taht for a while now."
email me with your dealer's name so I can stay away.
Good luck,
Pokey, also in TX
jrpoux@wcnet.net
I am a reliability specialis and this is the kind of problem I work on every day. Here are some thoughts:
The system has a pressure relief valve that opens if pressure is too high. If this is sticky you could have implement bouncing causing some problems.
Some systems also have thermal relief valves that open if the oil temp gets too high. To me, 210 sounds high. This is some good information to get from Kubota. Try to get a spec for maximum alowable oil temp. I would like to see gear box oil temperatures below 180 F.
Keep in mind two thoughts:
1. Water boils at 212F at atmospheric pressure. Steam is compressible, so it does not work well in a hydraulic system. A very small droplet of water can flash to a big steam pocket that could cause this problem.
2. Lowering the pressure on the water, or oil for that matter, also lowers the boiling point. The pump suction has a lower pressure than atmosphere. Actual pressure will depend upon the size of the fluid lines, restrictive effects of fittings and bends, and will be lowest at inlet to the pump mechanism. Flashing in your pump inlet could cause loss of pressure and will definitely reduce equipment life. Oil flashes easier at higher temperatures.
Some things you can do:
1. Call the oil manufacturer and ask to talk to an application engineeer. Inquire about the maximum operating temperature for the oil.
2. Consider changing brands of oil. Buy quality. Kubota UDT may not be. Yes it is expensive. Are $57 bolts quality or just expensive?
3. Send out two samples of oil for analysis. One sample of new, fresh oil, one from your tractor. Compare. Ask for moisture content, which will be parts per million (ppm) or possibly percent.
4. Consider installing an oil cooler in front of your radiator. This can be tricky if you live up north, because you can cool the oil too much in cold months. On a car, you always install the trans cooler such that the oil passes through the cooler and cools off, then passes through the radiator exchanger. The oil heats back up to your coolant temperature. This trick also adds radiator cooling capacity.
John Drre 5400 series have a trans oil cooler in front of the radiator.
At our plant we buy muilti-million dollar machines, spend months finding and fixing these kind of problems, then have the equipment manufacturers asking us "Have ya'll had that xxx problem happen any more? You have quit asking questions about that system?" My reply: "Strange, come to think of it, no we have not seen taht for a while now."
email me with your dealer's name so I can stay away.
Good luck,
Pokey, also in TX
jrpoux@wcnet.net
Thanks. Which office is Terence Chris with? I'd be interested in the fix. Is Kubota being secretive about it? Like maybe they don't want the fix to get around? You would think that they would contact me once they have figured this out. But I won't wait. Hopefully they will put out a service bulletin or something on it.
I wonder if they will apply the fix to my tractor, because in my case they deny any failures. They tested my tractor, but not long enough to duplicate the problem then declared me a liar.
Alan L., TX
I wonder if they will apply the fix to my tractor, because in my case they deny any failures. They tested my tractor, but not long enough to duplicate the problem then declared me a liar.
Alan L., TX
ronjhall
Super Star Member
Alan
Terence is out of <font color=orange>Kubota</font color=orange> in California. If you saved your customer satisfaction form, his name and their phone number is on the cover page. I’m not at my desk today. If you can’t find the number I can post it tomorrow evening.
Terence is out of <font color=orange>Kubota</font color=orange> in California. If you saved your customer satisfaction form, his name and their phone number is on the cover page. I’m not at my desk today. If you can’t find the number I can post it tomorrow evening.
