L3901DT Hydraulics Not Working

[Ricklesss]

Very much obliged Dan.
I will try that later today.
It occurred to me: Last fall I was swapping the hydraulic log splitter between this tractor and an old John Deere Hydrostatic tractor, and not thinking anything about it.
Until I realized that I was also trading “bodily fluids” between them.
I now understand that Kubota uses a hydrostatic oil and the Deere uses a fluid.
And probably not totally compatible.
I am planning on doing a full hydro oil and filter change.
I wonder if the two fluids aren’t playing nicely at the moment.
Thank you again.

 

[TheOldHokie]

Very much obliged Dan.
I will try that later today.
It occurred to me: Last fall I was swapping the hydraulic log splitter between this tractor and an old John Deere Hydrostatic tractor, and not thinking anything about it.
Until I realized that I was also trading “bodily fluids” between them.
I now understand that Kubota uses a hydrostatic oil and the Deere uses a fluid.
And probably not totally compatible.
I am planning on doing a full hydro oil and filter change.
I wonder if the two fluids aren’t playing nicely at the moment.
Thank you again.

I got considerable money that says its not the fluid

So how do you hook up that log splitter? Thats a new wrinkle in the plumbing.

Dan

 

[Ricklesss]

I disconnect the hose from the quick connector, (kind of under the seat), plug in the backhoe or log splitter hose into it, and then the plug the other line back to the tractor.
Dealer installed backhoe, and it and the splitter have always worked very very well.

 

[TheOldHokie]

I disconnect the hose from the quick connector, (kind of under the seat), plug in the backhoe or log splitter hose into it, and then the plug the other line back to the tractor.
Dealer installed backhoe, and it and the splitter have always worked very very well.

That connection would be suspect number one. Double triple check the rear outlet couplers are fully connected.

Dan

 

[Ricklesss]

I did not actually unplug and then plug it back in, because it sure LOOKS fine, and have ”looked” at it several times.
Ok, very first thing I will do is unplug and replug it back in.
Simpliest thing and all…
Thank you Dan, your incredibly helpful.
Rick in Oregon

 

[Ricklesss]

Dan! If your still out there and willing to give me just a tiny bit more advice please?
Being a total newbie at hydraulics I’ve really delved into learning how my system works and where all the hoses go. I’ve really been trying to learn!
I think I may have diagnosed what my problem is, wondering what you thought.
Both the inlet and outlet hoses on loader valve gush oil.
Neither the inlet (P) or the outlet (T) on W.L. Long spool valve flow at all.
Very importantly, I see my (top most) manual button on the spool valve is now stuck in. It was a little sticky before but now won’t pop out at all.
At one point pushing one of them in did open the grapple, but now neither seem to work.
Maybe I have a stuck spool valve?
Possibly a non functional solenoid?
I am going to call up W.L. Long to see how to test the solenoids.
Considering buying an entire new valve with solenoids, swapping it out and rebuilding mine for a spare.
MANY thanks if your still willing to guide a lost soul who really needs his tractor working!

 

[TheOldHokie]

Dan! If your still out there and willing to give me just a tiny bit more advice please?
Being a total newbie at hydraulics I’ve really delved into learning how my system works and where all the hoses go. I’ve really been trying to learn!
I think I may have diagnosed what my problem is, wondering what you thought.
Both the inlet and outlet hoses on loader valve gush oil.
Neither the inlet (P) or the outlet (T) on W.L. Long spool valve flow at all.
Very importantly, I see my (top most) manual button on the spool valve is now stuck in. It was a little sticky before but now won’t pop out at all.
At one point pushing one of them in did open the grapple, but now neither seem to work.
Maybe I have a stuck spool valve?
Possibly a non functional solenoid?
I am going to call up W.L. Long to see how to test the solenoids.
Considering buying an entire new valve with solenoids, swapping it out and rebuilding mine for a spare.
MANY thanks if your still willing to1a guide a lost soul who really needs his tractor working!

I would say you have found your problem. Disconnect power to the pushbutton (temove the inline fuse) and see if you can manually center both ends of the solenoid valve. Then try tje loader again.

You are clearly beginning to understand the circuit!!!!

Dan

 

[Ricklesss]

Dan, THANK YOU. I hope somebody helps you some day when you need it!
After watching a few YouTube videos, I removed and disassembled my W.R Long spool valve.
It had a very small piece of debris that was causing the spool to not center itself.
I used a probe and lifted it out then sprayed it with carburetor cleaner, assembled it and it WORKS!!
Pretty dang proud of myself, my first hydraulics repair!
I now have a hand drawn map I made of my entire tractor, done in an interest of learning how it all works. Previously all a mystery.
I did have a scare though, when I noticed everything was working except the three point.
I had to think about it for a good hour, then realized I had inadvertently locked it by turning that knob under the seat, thinking it was for the front end loader.
Thanks again for helping me!
Rick in Oregon

 

[TheOldHokie]

Dan, THANK YOU. I hope somebody helps you some day when you need it!
After watching a few YouTube videos, I removed and disassembled my W.R Long spool valve.
It had a very small piece of debris that was causing the spool to not center itself.
I used a probe and lifted it out then sprayed it with carburetor cleaner, assembled it and it WORKS!!
Pretty dang proud of myself, my first hydraulics repair!
I now have a hand drawn map I made of my entire tractor, done in an interest of learning how it all works. Previously all a mystery.
I did have a scare though, when I noticed everything was working except the three point.
I had to think about it for a good hour, then realized I had inadvertently locked it by turning that knob under the seat, thinking it was for the front end loader.
Thanks again for helping me!
Rick in Oregon

You are more than welcome and happy that you have it fixed,. Over the course of 50 years in the tech busuness I have been helped by countless people - just paying it forward.

That thinking thing can be scary but its so rewarding when it all falls into place

Dan

 

[JohnMackenzie]

Well to get back at you Dan, I have a screen on my hydraulic suction tube where it goes into the transmission. Its the solid tube that is bolted into the right side of the trans that goes directly to the hydraulic filter block, maybe its an aftermarket thing that my dealer put on for me, I know that you can buy them from some Kubota parts suppliers, I don't know, but I do know that with the Hydro trans on most older tractors that it is a standard thing on the left side of the trans coming from the suction tube for the hydro drive side, to be fair I've never owned a Hydro Kubota, its easy to trace back from your block, look for your filter and follow the big solid tube back leading into the transmission. Sorry for the late response boys, but I've been tractoring. Also I'm glad that this post helped other people as well, I'm glad that I wasn't the only one who had this problem. Also yes, my brakes were screwed, someone left the park brake on, I don't think I'm going to lend the tractor out to anyone unless I'm there to supervise. Regardless, thanks everyone, and to people in the future, I hope we all helped. John

 

[TheOldHokie]

Well to get back at you Dan, I have a screen on my hydraulic suction tube where it goes into the transmission. Its the solid tube that is bolted into the right side of the trans that goes directly to the hydraulic filter block, maybe its an aftermarket thing that my dealer put on for me, I know that you can buy them from some Kubota parts suppliers, I don't know, but I do know that with the Hydro trans on most older tractors that it is a standard thing on the left side of the trans coming from the suction tube for the hydro drive side, to be fair I've never owned a Hydro Kubota, its easy to trace back from your block, look for your filter and follow the big solid tube back leading into the transmission. Sorry for the late response boys, but I've been tractoring. Also I'm glad that this post helped other people as well, I'm glad that I wasn't the only one who had this problem. Also yes, my brakes were screwed, someone left the park brake on, I don't think I'm going to lend the tractor out to anyone unless I'm there to supervise. Regardless, thanks everyone, and to people in the future, I hope we all helped. John

I had to find an actual picture of the pipe to see what you are talking about. Are you saying there is a screen on the end of the pipe? That makes sense but is different from the older models where it was a separate part in and of itself. Looks likevI got fooled by the parts drawing.

I will have to look more closely at the maintenance schedule - I dont recall seeing any mention of cleaning that. Was yours clogged and the source of your problem?

Dan

 

[JohnMackenzie]

I had to find an actual picture of the pipe to see what you are talking about. Are you saying there is a screen on the end of the pipe? That makes sense but is different from the older models where it was a separate part in and of itself. Looks likevI got fooled by the parts drawing.

I will have to look more closely at the maintenance schedule - I dont recall seeing any mention of cleaning that. Was yours clogged and the source of your problem?

Dan

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Yeah it has on on the end of the pipe, I looked at the parts breakdown to make sure I'm not crazy, there isn't a screen in the pictures so my dealer must've put one on for me, I didn't take a picture when I had it apart. Being in Canada there's a few things my local dealer adds before they sell any equipment like a block heater and a radiator cover for the cold weather here, they also don't sell anything with a loader without adding the ssqa, I'm thinking there might've been a few extras that they didn't tell me about

 

[TheOldHokie]

Yeah it has on on the end of the pipe, I looked at the parts breakdown to make sure I'm not crazy, there isn't a screen in the pictures so my dealer must've put one on for me, I didn't take a picture when I had it apart. Being in Canada there's a few things my local dealer adds before they sell any equipment like a block heater and a radiator cover for the cold weather here, they also don't sell anything with a loader without adding the ssqa, I'm thinking there might've been a few extras that they didn't tell me about

Back to the main issue - was your loss of function caused by the screen being clogged?

Dan

 

[JohnMackenzie]

Back to the main issue - was your loss of function caused by the screen being clogged?

Dan

I'm not sure which one it was exactly because I cleaned it and changed the filter at the same time, probably a combination of the two. Regardless it was caused by someone driving with the parking brake on and ruining my brakes which caused the particles to block flow to the pump, not sure if it caused damage to it, but it's been working for the last 20 working hrs