2910 Steering problem

[ronjhall]

My 2910 steering has times when it is hard to turn after about 1 hour of mowing lawn. It appears to be a power steering problem. It started to show up when tractor had 30 hours on it. I now have 40 hours. I thought cooling was the problem, but cleaning grill and other inlets made no change. Checked oil level. It is at correct level. This week when I mowed lawn with temperatures in the 60's. Had the same problem. Put my hand on the 2 rear filters. The one on the right side was much hotter. I believe this is the power steering filter. Don't know if this is a problem or not?
I have been following the thread on the 2710 steering problems but have not seen any messages that say problems is solved.
My Dealer has called the Kubota Rep. But has not recieved a response as of yet.
Does anybody have any suggestion or resolved this problem other than get a larger tractor?


ronh

 

[Bird]

ronjhall, my B2710 has a single hydraulic filter and someone (now I've forgotten who) posted a new page for the parts manual showing the replacement parts to put 2 two filters on it. Of course, the B2910 has two filters to start with. I've asked the service manager at two dealerships about the problem. The first one said, "Sounds like air in the system," and the second one asked, "Did you change the filter when it happened?" He said anytime there is a hydraulic problem, changing the filter is the first thing you do. Both of them claimed to have never heard of this problem from either customers or Kubota.

Bird

 

[Ian]

ronh: I had the dealer look at my B2710 which had the same steering problems that you describe. They modified the tractor by replacing the right hand hydraulic fluid strainer with a cartridge filter, and changed the supply line from the filter to the power steering pump.

It seems that this is the set up that is standard on the B2910.

It's too early to tell if the fix worked, since the fall temperatures are much cooler, and the grass has stopped growing. I'll update the thread in the spring.

I posted the diagram from the shop manual towards the end of the 'B2710 Stering problems' discussion.

If the fix dosen't work, I'm going to try synthetic oil in the transmission next summer, assuming Mr. Kubota has no other ideas.../w3tcompact/icons/smile.gif

I think that the problem was also reported in the archives by someone living in Australia, but I forget if the tractor was a B2710 or a B2910.

Ian

 

[ronjhall]

Thanks for the replies. My dealer picked up my tractor and did all kinds of test before doing any repairs to it. Did not find anything wrong. Did the 50 hr inspection,and oil, filter change. He returned it Thursday. Cut the lawn with no problems. My dealer was not happy with Kubota's response to this problem. But until next summer when I get some hours on the oil and filters again. I will see how things turn out. My dealer did say he had another 2910 that had the same problem. Used the same fix to get rid of steering problem.

ronh

 

[Anonymous Poster]

Hey guys, I've heard of two tractors so far with the "steering problem" you're all describing. One was a B2710, and one was a B2910 with the "updated filter set up". Yes, all the new tractors are coming through with the new filter set up. BUT THAT IS NOT THE FIX..... There is no service bulletin to upgrade to the new filter set up as I've seen mention of in previous posts. Trying different fluids is not going to work. Had a customer bring his B2710 in with the problem. I took the machine out for a test run, after approx. 45 minutes I got the machine to perform the described problem. Drive the tractor in a straight line for about 40 yards and make a sharp turn (as if you're turning for your next mowing pass)
The outside air temp at the time was approx 75 degrees. That's when it shows up (feels like steering power goes away for a few seconds then comes back). Noticed it only happens in left turns (Hmmm..what side is the mower discharge chute?) Also, at an idle, tried the quick turn to the left and geuss what? same problem, but only to the left. Soooo.. now I,m thinking the port for left turns must be further away from the source of flow than the right port, but if the breakdown in the manual is correct- that is not correct, the left turn port is closer, so much for that idea. Bumped up relief pressure to see if that would have any effect-no change. Lowered relief pressure-no change. Now I'm thinking cavitation/starvation but what's bugging me a little is when a pump cavitates you can hear it, usually makes a barking/chirping sound. OK, let's check pump flow output. (you all do realize that that's a dual pump set up, the front section is for hyd ops and the rear section is dedicated to steering) Flow test the power steering section of the pump and my numbers come out a little low, and I do mean a little low. Under normal circumstances I would'nt have even considered it a problem, but everything else checked good. Removed and dis-assembled the pump and found some very minor scratches in the housing. Replaced the hyd pump and noticed a difference right away. Idle steering was better, tested for at least one hour, same air temp, and could not duplicate the problem. Delivered the machine back to customer and followed up with him about 2 weeks later, he stated that he too noticed an improvement in steering right away and has not been able to duplicate the problem. I'ts been at least 3 months, and I have not heard back from him (which is good news, I hope) Now before you guys go scrambling to your dealers for new hyd pumps, I'm not totally convinced that a new pump will solve this problem. Although it appears in this case to have done just that. My customer has'nt had a full mowing season to effectively check the results of this repair. I do not know the results of the B2910 mentioned earlier (another dealer). What I'd like to know from you guys that are having problems is: Does your failure mimic the previously described symptoms, what is your model and serial number, note atmospheric conditions, throttle positions, all variables you can come up with. We sell
ALOT of these tractors and I'm very interested in this particular problem.

 

[Bird]

kub-mech, my tractor is a 1999 B2710HSD, serial number 12429, and I've only encountered that little steering problem twice in 200+ hours. Both times the temperature was about 90F (plus or minus 5 maybe), mowing with a 5' brush hog, engine running at PTO speed, light mowing with no load on the engine and running in high range just a little faster than the maximum I could get in low range (maybe 6 mph?). The first time was in my own pasture and doing 180 degree turns to the right on level ground. The second time was in someone else's pasture with everything the same except I was going slightly uphill and making 270 degree turns to the left. The first time it happened, I had been running non-stop for a little less than 2 hours. The second time, I had been running non-stop for about 4 hours. And both times, I had the cruise set and was using the right or left brake for faster turning (which is something I rarely do). I never noticed it while running fairly straight or while making pretty wide sweeping 90 degree turns. And while I don't like any little problem like that, I know how tough it can be to find something that happens that rarely. In fact, I haven't taken it to the dealer because I'm not sure I (or they) could duplicate the problem if we tried. Is there a possibility that the use of the brake had something to do with it? I don't recall that being mentioned by the others, and don't think I thought of it or mentioned it either in the past.

Bird

 

[ronjhall]

kub-mech: My 2910 was purchased last May. Serail # 50361. My problems are similar except both directions can have the problem. Ounce it starts happening it will not go away until the tractor has cooled down. The right filter gets hotter than the left. Next time I get it hot I intend to check the difference with a temp probe. Whenever it happens I have been using the tractor for over an hour. I cut about 2 acres of lawn. Lot of short open areas and items to avoid. I run the engine at PTO speed (2600 RPM). Use mid range speed and run as fast as mower can cut. Usually from about half to full movement of HST pedal. My dealer was able to get problem to show up slightly after mowing his lawn.
The other tractor that showed at this dealer was using a FEL with a load in the bucket whenever it showed up. The owner uses it in a landscape business. To get him running oil and filters were changed.
Except for this problem I'm very happy with my 2910. Have FEL, 72" mid mower, 60" bush hog, and several 3ph tools for ground work.


ronh

 

[Anonymous Poster]

Thanks for the info Bird,
I don't think using the brake for quicker steering would contribute to the problem other than adding a bit more heat to the reservoir, thus raising the fluid temp.

 

[Anonymous Poster]

Right filter is for hyd sytem; loader, power steering, 3ph,
anything running off power beyond circuit. Left filter is dedicated to HST system only.
thanks for the info

 

[Bird]

Incidentally, kub-mech, since my B2710 is a 1999 model, it doesn't have the dual filters; just one and the strainers.

Bird