Kubota BX25DLB 4IN1 Stopped working

[kangadigger]

Hi everyone!

I'm working on my father's Kubota BX25DLB, and I am hoping I can ask some advice about how to fix the 4in1 bucket which has stopped working. All other hydraulic functions appear to work fine. Relevant background below. :

1. He absolutely loves his little orange tractor and recently did some work grading his driveway, which is when the 4in1 bucket grapple function stopped working.

2. All other hydraulic functions work fine.

3. His model has a Kubota 1200mm 4in1 Bucket with a front control loader with two buttons to operate the grapple function. Pressing these buttons no longer work to open or close the bucket.

4. I researched what to do, and thought maybe he accidentally disconnected the hoses partially (apparently this can happen) ... I disconnected and connected the hydraulic lines several times, but it didn't fix it.

5. I disconnected the hydraulic line at the 4in1 bucket in case it was locked up, and bled the line ... nothing wrong with the hydraulic piston. It can be manually opened and closed by hand (heavy though) ... so I don't think he backdragged it and broke that part. It appears to be lack of flow into the hydraulic hose. Not sure if have to flush the air out after reconnecting. I did top up the hydraulic oil reservoir and ran the machine in neutral and exercised all the bucket boom lift functions ...

6. I used a multimeter to test the switches worked for the grapple function. They appear to have continuity so the switches work mechanically to shunt signal. I redid the electrical lines to the front control valve assembly thing... I think the wires are not the problem.

Not sure about the power or signal or where it goes ... all I know is that a ground wire comes from under the engine cover and goes up the lever stalk where there is a left and right button, and each of those signal wires go into the pictured front loader control valve box thing. I actually am not sure what it is.


I am kind of stumped. I'm handy but not a hydraulic expert and first time tractor owner. I would be grateful if anyone help advise me of a few ideas to figure out what is going on? The unit only has 350 hours, and has been babied until recently when we acquired it second hand. My father might have been a bit rough as he is still learning to use it. I am keen to learn how to fix it myself. I have looked over the WSM and the Operator Manual but I am not sure what to do at this point ...

 

[DustyRusty]

Did you check the fuse block? I have a blown fuse this past week, and hunted for an hour, until I found it. It was tucked under and behind a wire bundle, and couldn't be seen. All the fuses in the fuse block checked out OK, but it was a main fuse that had blown.

 

[Dave_eng]

You need to have a 12 volt test light to troubleshoot problems like this.

These cost less than $20 at all auto parts places and on line.

You connect the alligator clip to the battery ground cable and touch the pointed tip to the switch contacts for your bucket valve often called a third function valve.

Your problem is not hydraulic so dont go and make things worse by opening hydraulic lines. You run the risk of mis connecting something.

Focus on the electrical signal to the two solenoids controlled by the two push buttons.

Dave

 

[kangadigger]

Did you check the fuse block? I have a blown fuse this past week, and hunted for an hour, until I found it. It was tucked under and behind a wire bundle, and couldn't be seen. All the fuses in the fuse block checked out OK, but it was a main fuse that had blown.

Hi Dusty! Thanks for following up. Yes and No.

I checked the main fuse box as a first thing. All fuses good. However I think you are onto something.

What I have learned
I have learned more about this function, and it appears to be an optional extra accessory known as a '3rd function valve kit'. This tractor was sold by Kubota Australia and we acquired it second hand private, but appears to be somewhat rare as having all these accessories.

Most people here apparently do not get a 4in1, and I think that the local dealer must contract outsource a local hardware manufacturer to add on the 4in1 bucket and third function kit.

Reason I say this is because the remote (buttons) on the front loader control stalk do not correspond to any official Kubota parts lists that I can access using the overseas Canada/USA site. That said, I think this is an 'official' local accessory sold by Kubota, but as a kit - there does not appear to be a manual for it in the standard Kubota online documentation.

Answering your question, good point! I now believe that there must be a fuse for this thing that could have blown. Also as an add-on kit, I think you might be right that there could be a hidden fuse somewhere around the vehicle that I need to find. This would make sense because despite the switches working for continuity (I mean the switches appear to function mechanically if not functionally) there does not appear to be a steady voltage in that circuit (there is a wavering voltage of a few millivolts which might be my multimeter picking interference) ... and no clicking in that mystery black box when I press the button. I have also now learned that this mystert box that the remote on the stalk connects to must be the 'solenoid block'. This is the video I watched to learn more.

My next step will be to trace the wiring and see if there is a fuse somewhere .. really hoping it is just a blown fuse!

 

[kangadigger]

You need to have a 12 volt test light to troubleshoot problems like this.

View attachment 64194

These cost less than $20 at all auto parts places and on line.

You connect the alligator clip to the battery ground cable and touch the pointed tip to the switch contacts for your bucket valve often called a third function valve.

Your problem is not hydraulic so dont go and make things worse by opening hydraulic lines. You run the risk of mis connecting something.

Focus on the electrical signal to the two solenoids controlled by the two push buttons.

Dave

Hi Dave! Thanks for the advice - I promise I will go to the autoparts store and get one of those immediately. I will report back with my findings!

 

[DustyRusty]

Hi Dusty! Thanks for following up. Yes and No.

I checked the main fuse box as a first thing. All fuses good. However I think you are onto something.

What I have learned
I have learned more about this function, and it appears to be an optional extra accessory known as a '3rd function valve kit'. This tractor was sold by Kubota Australia and we acquired it second hand private, but appears to be somewhat rare as having all these accessories.

Most people here apparently do not get a 4in1, and I think that the local dealer must contract outsource a local hardware manufacturer to add on the 4in1 bucket and third function kit.

Reason I say this is because the remote (buttons) on the front loader control stalk do not correspond to any official Kubota parts lists that I can access using the overseas Canada/USA site. That said, I think this is an 'official' local accessory sold by Kubota, but as a kit - there does not appear to be a manual for it in the standard Kubota online documentation.

Answering your question, good point! I now believe that there must be a fuse for this thing that could have blown. Also as an add-on kit, I think you might be right that there could be a hidden fuse somewhere around the vehicle that I need to find. This would make sense because despite the switches working for continuity (I mean the switches appear to function mechanically if not functionally) there does not appear to be a steady voltage in that circuit (there is a wavering voltage of a few millivolts which might be my multimeter picking interference) ... and no clicking in that mystery black box when I press the button. I have also now learned that this mystert box that the remote on the stalk connects to must be the 'solenoid block'. This is the video I watched to learn more.

My next step will be to trace the wiring and see if there is a fuse somewhere .. really hoping it is just a blown fuse!

Look in the battery compartment for a relay, that has 2 12 gauge red wires. One is power to the relay, and the is power out on the relay. Using my BX23S as an example, there is a purple wire in the middle of the dash hanging down, and that should have another wire plugged into it, color unknown, that is the trigger wire from the ignition switch to the relay. Using the test light, check that wire for power, first where it originates at the dash by unplugging it, and then look for a hot lead at the relay. If there is only one wire that is "hot" at the relay, then it is definitely a blown fuse. On my tractor, it was a 25 amp ATC fuse. The ATC fuses have a tiny hole at each end, where you can touch with the test light to check to see if the fuse is good or bad. If there is power at only one side of the fuse, then you know that is a defective fuse. If it lights on both ends, then it is a good fuse. In the fuse block on my BX23S, there is a single 10 amp fuse specifically marked for the 3rd function feature. Here is an explanation of all the different types of fuses that you might encounter on your tractor.

Automotive fuse - Wikipedia

en.wikipedia.org

I strongly suggest that you only purchase known brands of fuses, because today there are a lot of cheap imitation of quality fuses. I only use Cooper Bussmann or Littlefuse packaged products. A few years ago, GM dealers were buying inexpensive bulk fused to repair cars, which lead to a lot of wiring fires. It got so bad that GM sent out a technical service bulletin warning the dealerships of these fakes, and instructed them to only purchase fuses from GM parts depot, where they were assured of getting the quality part.
Look for Cooper Bussmann ATM 42-Piece Automotive Mini Blade Fuse Kit with Fuse Tester_Puller-NO.43 . Littlefuse also makes a similar kit of fuses, and they sell for $22 US approx.

 

[DustyRusty]

I believe that I have found the manuals for your tractors 4 in 1 bucket.

Operators Manual

https://cdn-assets.greatplainsmfg.com/ari/attach/lp/public/manuals/381-139m.pdf

Parts Manual

https://cdn-assets.greatplainsmfg.com/ari/attach/lp/public/manuals/381-139p.pdf

3rd Function Installation & Parts Manual

https://cdn-assets.greatplainsmfg.com/ari/attach/lp/public/manuals/380-145m.pdf

 

[kangadigger]

Dear DustyRusty, Dave_eng,

Solved: Hidden Fuse!

Thank you guys so much for your helpful advice. I really hope I can contribute in future with helpful advice also as I learn more about how to look after and use this wonderful machine.

Just providing an update because I hate it when people ask questions and never check back in to update. Also because it is useful to provide answers in case someone else has the same problem in future.

I followed Dave_Eng's advice and bought myself a test probe light, and I also followed DustyRusty's advice and traced the wire back to the battery. I know it looks obvious but the fuse was tucked in and hidden, plus the original fuse was colored black instead of the bright orange I have replaced it is. Do not worry - I have put in a brand fuse!

There I found a fuse as pictured below, and thankfully it proved to be a very simple case of replacing that part and refilling the hydraulic oil I had spilled out when I had messed around with the hydraulics.

I suspect the fuse burned out since the wires connecting the remote to the third function solenoid valve was frayed and rubbing against each other showing naked wire. Either that or my Dad burned the thing out trying to be too rough using the grab function of the 4-in-1.

I have attached some photos below. Just as a point of note, I have used XT60 connectors (for RC Hobby plane batteries) to redo the connections until my order of Deutsch/Car Crimp connectors can be ordered. I have done some research and apparently these are what are used on Caterpillar Excavators and a good choice for anyone thinking of reconnecting wires...

So glad to find it was not hydraulic ... I learned a lot about what a third function solenoid valve and about the 4-in-1 bucket, thank you for helping me. I have downloaded the manuals, so thank you again.

Thanks again Dave and Dusty!

 

[Dave_eng]

Thank you for providing the final chapter. It helps everyone learn. Unfortunately a few come on the forum seeking help, get a solution and just vanish.

Dave

 

[kangadigger]

Thank you for providing the final chapter. It helps everyone learn. Unfortunately a few come on the forum seeking help, get a solution and just vanish.

Dave

Thank you Dave! I am the one that is thankful! See you guys on the forums :-D

 

[DustyRusty]

Glad to be of assistance. I had the same problem, and I originally thought it was the relay, only to find the fuse hidden behind the wire bundle lying on the floor of the tractor. I have since used a nylon wire tie and have tied the fuse to the dash support that resides in front of the battery. In my case, it was a 25 amp master fuse that had blown, as a result of my negligence when hooking up a switch. I was installing a Carling switch to control my rear LED lighting, and this switch was a 4 terminal switch, and I assumed that it was wired similar to the wiring of the 3 terminal switch. Once I found the wiring diagram for that particular switch, I realized that I had connected the positive (+) wire directly to the ground wire (-). Should have known better than to assume.