Backhoe swings right, but not left

[workinallthetime]

i just did the 400 hr service, the issues still happens but after filing with udt2 the BH recovers with one swing in the other direction. i have narrowed the issue down to when it is warm and i go full right to the stops.

 

[KubotaToy]

I have had problems with the boom control valve reliefs on my L45 over the past few years. They seem to lift early and then stick open. I take them off and clean them up and I am good for a while. I switched to SUDT2 at 200 hours, I like SUDT2 for winter operation but not sure about hot summer yet.

 

[Hersheyfarm]

I have had problems with the boom control valve reliefs on my L45 over the past few years. They seem to lift early and then stick open. I take them off and clean them up and I am good for a while. I switched to SUDT2 at 200 hours, I like SUDT2 for winter operation but not sure about hot summer yet.

My boom was leaking off, turned out to be some rubber pieces in the relief valve. Took all of them of, cleaned some rubber out of some but I also adjusted them. Really good response now. I don't think they were ever adjusted from the factory. The bottom three are really hard to get too. Have to take the whole control block off.

 

[Stonehaller]

i have narrowed the issue down to when it is warm and i go full right to the stops.

The swing valve has work port relief valves with anti-cavitation checks. I suspect the port relief for the RH side is getting stuck open when the valve is hot. The port relief should be set to 2700-2770 psi which is higher than the swing pump relief (2500 psi) so it should not open if you stall the swing into the stop. The main swing relief should open first. (Pressure values are from the L39 manual, but I believe the BT1000 is backhoe is the same for the L45).

It sounds like the dealer already tried cleaning the valve. You may have to just replace it. You could try cleaning it again, and screwing in the adjustment a little to increase the pressure setting so it does not prematurely open.

 

[workinallthetime]

Sitting at 775 hours now, I have had the issue probably 6 times since I originally reported it. I have noticed that the bh will start creeping to one side while driving and I know it is about to happen. I push the bh to left and carry on. When I store it I push the BH all the way to the left and typically don’t have a problem the first day out, I need to just have it replaced but if I can keep it going as is for another 400 hours I will just buy a new L47......or

 

[mikester]

Sitting at 775 hours now, I have had the issue probably 6 times since I originally reported it. I have noticed that the bh will start creeping to one side while driving and I know it is about to happen. I push the bh to left and carry on. When I store it I push the BH all the way to the left and typically don’t have a problem the first day out, I need to just have it replaced but if I can keep it going as is for another 400 hours I will just buy a new L47......or

If you leave the engine at low idle and try the swing in both directions do you hear or notice any change in the engine rpm? Does it bog down a little I.e. does one circuit sound like it’s getting loaded but not the other? Does it sound the same in both directions? Does the problem only occur when the tractor is hot? Ie. after running a while

 

[workinallthetime]

I will have to check, when I pull the valve out you can see it is stuck in the extended position. I let it cool down and tap on the side of it and it returns to normal. Kubota wants 400+ for a new valve