STRANGE Hydraulic Issues on L48/BT1100

[DannyNewmanL48]

I checked swing cylinder hose routing probably 5 times and it matches the Kubota diagrams to a tee. There are no issues there.

Yes, each time I have taken the valve stack apart I ensured that the load checks and their springs were in place and correctly oriented. Right now, I have the valve stack disassembled again, and I’m looking closely at all of the passages inside the mid inlet to make sure everything looks correct. I REALLY do not want to pull this valve stack off the hoe again after I reinstall it. I’ve had this thing apart way too many times trying different configurations. But hey, at least my muddled incoherent swapping did confirm that the swing spool valve isn’t bad, the overload relief valves aren’t bad, and the issue is not specific to one cylinder.

And here’s the truth: with the lack of casting numbers or Husco identification numbers provided by Kubota in their literature, I have no way of definitively knowing what valve is supposed to be where. Husco doesn’t stamp a Kubota part number on these valves and Kubota doesn’t give you the Husco numbers either. All I know is the configuration that everything was in when I first brought it home. Someone has been in here before as you know, how do we know they reassembled it the right way? How do we know they replaced that one spool with the correct part? Sure it looks right, but is it made to the right spec? Kubota and Husco give us no way to know… They just want you to fork over $3,400 for a new set of valves.

 

[PoTreeBoy]

Danny, humor me. While you have the valve disconnected put the swing hoses in the catch bucket. Then, by hand, push the boom to one side. Does fluid come out of one hose? Then push the boom all the way to the other side; does fluid come out of the other hose?

 

[TheOldHokie]

I checked swing cylinder hose routing probably 5 times and it matches the Kubota diagrams to a tee. There are no issues there.

Yes, each time I have taken the valve stack apart I ensured that the load checks and their springs were in place and correctly oriented. Right now, I have the valve stack disassembled again, and I’m looking closely at all of the passages inside the mid inlet to make sure everything looks correct. I REALLY do not want to pull this valve stack off the hoe again after I reinstall it. I’ve had this thing apart way too many times trying different configurations. But hey, at least my muddled incoherent swapping did confirm that the swing spool valve isn’t bad, the overload relief valves aren’t bad, and the issue is not specific to one cylinder.

And here’s the truth: with the lack of casting numbers or Husco identification numbers provided by Kubota in their literature, I have no way of definitively knowing what valve is supposed to be where. Husco doesn’t stamp a Kubota part number on these valves and Kubota doesn’t give you the Husco numbers either. All I know is the configuration that everything was in when I first brought it home. Someone has been in here before as you know, how do we know they reassembled it the right way? How do we know they replaced that one spool with the correct part? Sure it looks right, but is it made to the right spec? Kubota and Husco give us no way to know… They just want you to fork over $3,400 for a new set of valves.

There is no mysterious Kubota specificatiion. Your problem is in the swing circuit and thats where you should be looking for your problem. Test the external operation before taking valves apart. You bought a hoe with a checkered past and I appreciate your frustration but rants arent going to fix anything.

Dan

 

[PoTreeBoy]

I checked swing cylinder hose routing probably 5 times and it matches the Kubota diagrams to a tee. There are no issues there.

There are other possibilities besides wrong connections. You gave the facebook group a week to shotgun it (with a couple of possibilities). There's more expertise here, I'm not including myself, and we'll get you going if you'll work our system.

 

[TheOldHokie]

Simple question - does the swing valve deadhead with both hoses disconnected at the cylinders?

Dan

 

[ruger1980]

As stated STOP messing withe the control valve. The other circuits have nothing to do with the swing function. The only commonality is that the return from all circuits to tank merges before leaving the valve. Everything you need to diagnose this issue is in the schematic that @whitetiger posted which should be in the WSM that you have.

If the couplers were the issue the pump should be running over relief all the time. Is this the case?

What Dan asked above is a decent test. But also check that flow is present for alternating hoses when left and right swing function is actuated.

 

[TheOldHokie]

As stated STOP messing withe the control valve. The other circuits have nothing to do with the swing function. The only commonality is that the return from all circuits to tank merges before leaving the valve. Everything you need to diagnose this issue is in the schematic that @whitetiger posted which should be in the WSM that you have.

If the couplers were the issue the pump should be running over relief all the time. Is this the case?

What Dan asked above is a decent test. But also check that flow is present for alternating hoses when left and right swing function is actuated.

I will add one more step to @ruger1980 's test.

After verifying you are getting alternating flow connect just one swing cylinder hose and see if the boom will swing in that direction.

Dan

 

[L35]

Don’t be one! Trust the process!

 

[ruger1980]

Don’t be one! Trust the process!

View attachment 173805

Let's not chase him away

 

[L35]

Let's not chase him away

Nobody is trying to chase anyone away, but if ya ask for help you need to accept the help that’s offered.

 

[Runs With Scissors]

Let's not chase him away

I agree, we all have to start somewhere…me included……….HOWEVER

Don’t be one! Trust the process!

View attachment 173805

That is just “plain ole funny”…..OMG…….. @L35 , you sir, owe me a keyboard cause the coveffee that just shot out of my nose has ruined mine!!!!!

I have never heard that term before…..

 

[North Idaho Wolfman]

Reel it in folks.

Danny some people are just trying to give you the best help that they can.
And others are well trying to lighten the situation up.

Please do not delete an active thread, it will help you or others down the line.

 

[PoTreeBoy]

Danny, if you're still there, do this:
Disconnect the swing cylinder rod ends from the swing frame. Remove the keeper bolts and knock the pins out. You may need some kind of prop so the rods are free to extend without hitting anything.

Then start the tractor and try to swing left. What does each rod do? Swing right, what does each rod do?