Occasional loss of hydraulics on B2710

[Alan L.]

I posted recently about my power steering going out and finding that I had lost a couple of quarts of UDT via a hole in a hose. Got that fixed and everything seems fine.

However something happened today that I am starting to get concerned about. I bottomed out the brush hog on a mound of dirt and killed the tractor. I was on an incline backwards and after I restarted the tractor I could not raise the cutter nor the FEL. Seems like I was able to move the tractor (hydro). After less than a minute it all suddenly strarted working again.

I don't believe this is related to my having run the UDT low the other day because it has happened 2 or 3 other times in the last several months. I frankly can't remember the conditions of the other times it happened, but seems like I might have killed the tractor on those occassions also. Maybe it just takes a little time to get the pressures flowing after that happens?

Any ideas on what could be causing this?

 

[ronjhall]

If your power steering stopped working because of low oil. It would take more than a couple quarts of oil to fill. Both power steering and FEL/3PH use same suction line. They have sperate output hoses. Make sure engine is off when checking oil level. You may need to do a oil change and clean suction filter.
You should be using Super UDT.

 

[Alan L.]

Ron, I did check the fluid level with the engine not running, but did not check it again after running the tractor after putting the hoses on. I will be sure and recheck before I run the tractor again.

I'm not sure what or where the suction filter is. I have two oil filters I change out when I change the fluid, per the power steering re-engineering Kubota did back when the tractor had 200 hours on it. They put a whole new gear box housing and replaced a screen on the side with a filter at that time. This was to correct the power steering problem I had back then, which you are familiar with.

As for the Super UDT, the tractor has mostly had super UDT in it, but my impression was that it is a cold weather oil. Haven't really had trouble with the PS recently but I seem to have had better luck with regular UDT back then. I am inclined to use the super if it has better heat characteristics. I think going ahead with a fluid change is a good idea, since I am only about 30 hours from needing to do it anyway.

 

[ronjhall]

Your right no screen.
For your tractor to start having power steering problems again oil would have to get very low. Since suction is in bottom of trasmission that means really low. May have be low enough to make oil cavitate though. Causing air bulbs in line. Which is what caused oringinal power steering problems. Every time mine went out changing oil out would fix problem for awhile until it got hot again.
Super UDT has much better high temperture characteristics than UDT.

 

[ozzie tractor]

i think we had this discussion before if i remember correctly. udt is for hot and sudt is for cold climate. im in oz and we only get udt. i have never seen sudt ever. in the discussion i think this ended up being put down to our climate, 90% of oz goes from about at worst 20 f to maybe 105 f.
as for the issues. i think the oil ran out of the pump and due t the incline and extra suction required it couldn't lift the oil for a while.
give it a service for a start and see. also check for leaks in the suction pipe (the big one going to the hyd pump).

 

[BubbaJr]

In addition to the other good advice, you may have air in the hydraulic system. The way to bleed the air out, is to put the front wheels of the tractor on some soft ground (to keep from scuffing the rubber off your tires), and turn the steering wheel lock to lock several times holding the wheel at the ends of its travel for a couple of seconds. This will burp the air out of the system.
But as you said if you are within 30 hours of changing the fluid, that would be a great idea.

Good Luck