Woods Backhoe BH80X lost swing

[kleduc1]

I have a '12 Kubota L3240 with a Woods BH80X backhoe that lost its swing to the left while very light stumping. Seemed bound up and hydraulics struggled with that function only (all other levers/pistons continue to work properly). I removed the piston pins to the BH and boom moves freely. It is a double piston push/pull setup. The right (looking down from the seat) piston does not extend under hydro pressure, but I can push it back in by hand with engine off and pushing the control stick. Wondering if the internal piston seals have failed, or something in the valve control body (like debris or seals).

Thanks for the help!

 

[TheOldHokie]

I have a '12 Kubota L3240 with a Woods BH80X backhoe that lost its swing to the left while very light stumping. Seemed bound up and hydraulics struggled with that function only (all other levers/pistons continue to work properly). I removed the piston pins to the BH and boom moves freely. It is a double piston push/pull setup. The right (looking down from the seat) piston does not extend under hydro pressure, but I can push it back in by hand with engine off and pushing the control stick. Wondering if the internal piston seals have failed, or something in the valve control body (like debris or seals).

Thanks for the help!

Like anything else test the hydraulic work circuit for that function. Measure hydraulic pressure on both hoses. That will tell a big part of the story

If you had a Kubota hoe it would have port reliefs on those hoses and they are a common point of failure. I would think Woods uses port reliefs as well but that is pure speculation.

Dan

 

[kleduc1]

Like anything else test the hydraulic work circuit for that function. Measure hydraulic pressure on both hoses. That will tell a big part of the story

If you had a Kubota hoe it would have port reliefs on those hoses and they are a common point of failure. I would think Woods uses port reliefs as well but that is pure speculation.

Dan

Installed a new piston and still no function to the left. Temporarily (30 seconds) lost boom lift function and then it came back. Next will be to open up the valve control body to see if debris is present or seals are worn. Boom lift valve is just left of the swing valve.

 

[TheOldHokie]

Installed a new piston and still no function to the left. Temporarily (30 seconds) lost boom lift function and then it came back. Next will be to open up the valve control body to see if debris is present or seals are worn. Boom lift valve is just left of the swing valve.

Taking things apart before testing function is always a better idea. JFYI - there are no pressure seals in that valve.

Dan

 

[PoTreeBoy]

Installed a new piston and still no function to the left. Temporarily (30 seconds) lost boom lift function and then it came back. Next will be to open up the valve control body to see if debris is present or seals are worn. Boom lift valve is just left of the swing valve.

Before you do that, take some pictures of the control valve from different angles. I'm with TheOldHokie, sounds like port relief issue. Maybe we can identify the valve and where any reliefs are.

BTW, how did you determine which piston to replace? They're probably piped in parallel, so some trouble shooting would be required to determine the faulty one, if either is.

 

[TheOldHokie]

Before you do that, take some pictures of the control valve from different angles. I'm with TheOldHokie, sounds like port relief issue. Maybe we can identify the valve and where any reliefs are.

BTW, how did you determine which piston to replace? They're probably piped in parallel, so some trouble shooting would be required to determine the faulty one, if either is.

I got the impression the swing uses opposed single acting cylinders.

Dan

 

[PoTreeBoy]

I got the impression the swing uses opposed single acting cylinders.

Dan

You got me thinking. Messicks has parts diagrams for the Woods BH80X. This hose diagram would indicate double-acting cylinders hosed in parallel, like my BT900.

And this diagram shows port reliefs, #2 & #3.

 

[TheOldHokie]

You got me thinking. Messicks has parts diagrams for the Woods BH80X. This hose diagram would indicate double-acting cylinders hosed in parallel, like my BT900.
View attachment 177693
And this diagram shows port reliefs, #2 & #3.
View attachment 177694

Well done. My money is still on a port relief failure. A simple pressure check at the work ports should answer that question.

Dan

 

[kleduc1]

Taking things apart before testing function is always a better idea. JFYI - there are no pressure seals in that valve.

Dan


First time trying to work on something like this so it's all new to me. Is it possible that it's just debris causing it not to work? The valve does not have any restriction with the lever when it is moved left to right. I did take out the top cylindrical thing and could see all the holes that lets the hydraulic fluid move to certain lines and did not see any debris. I'll remove it again and blow it out with air pressure before disassembling the entire valve body.

Thank you for all your help.

 

[TheOldHokie]

First time trying to work on something like this so it's all new to me. Is it possible that it's just debris causing it not to work? The valve does not have any restriction with the lever when it is moved left to right. I did take out the top cylindrical thing and could see all the holes that lets the hydraulic fluid move to certain lines and did not see any debris. I'll remove it again and blow it out with air pressure before disassembling the entire valve body.

Thank you for all your help.

It clear you are a newbie. I don't mean to be rude but if you want help stop throwing parts and taking things apart, Listen, and learn. You will resolve the problem quicker and at less cost.

Your swing cylinder valve is equipped with port reliefs. Thats probably the "cylindrical things" you removed. If they fail you wont get hydraulic pressure to your cylinder.

The first thing you should do is pressure test the line going to the swing cylinder thats not working. All it requires is a $15 gauge and some fittings. Disconnect the base end hose on the cylinder and connect your gauge to the hose. Operate the controls to extend that cylinder. You are probably going to see little if any pressure. Thats a good indicator the pott on that side of the valve is out to lunch.

Dan

 

[kleduc1]

It clear you are a newbie. I don't mean to be rude but if you want help stop throwing parts and taking things apart, Listen, and learn. You will resolve the problem quicker and at less cost.

Your swing cylinder valve is equipped with port reliefs. Thats probably the "cylindrical things" you removed. If they fail you wont get hydraulic pressure to your cylinder.

The first thing you should do is pressure test the line going to the swing cylinder thats not working. All it requires is a $15 gauge and some fittings. Disconnect the base end hose on the cylinder and connect your gauge to the hose. Operate the controls to extend that cylinder. You are probably going to see little if any pressure. Thats a good indicator the pott on that side of the valve is out to lunch.

Dan

Thank you

 

[kleduc1]

Thank you

Hopefully this will make you laugh.. a newbie for sure. I had turned the swing speed knob one turn slower and then it stopped working. I turned it back to faster and everything was operating normal. But I did take apart the cylinder things with the holes and blew out with compressed air I was on my way to get the gauge and fittings when I'm like okay let me try one more thing.

Thanks again for all your help.

 

[PoTreeBoy]

Hopefully this will make you laugh.. a newbie for sure. I had turned the swing speed knob one turn slower and then it stopped working. I turned it back to faster and everything was operating normal. But I did take apart the cylinder things with the holes and blew out with compressed air I was on my way to get the gauge and fittings when I'm like okay let me try one more thing.

Thanks again for all your help.

Thanks for letting us know. I didn't see that valve, it's on the hose and fitting diagram, #1.

I could probably use one on my BT900, it'll swing pretty hard if I'm not careful.

 

[TheOldHokie]

Hopefully this will make you laugh.. a newbie for sure. I had turned the swing speed knob one turn slower and then it stopped working. I turned it back to faster and everything was operating normal. But I did take apart the cylinder things with the holes and blew out with compressed air I was on my way to get the gauge and fittings when I'm like okay let me try one more thing.

Thanks again for all your help.

Sometimes its the simple stuff.

Dan