Kubota B3150 4in1 Bucket wont lift under certain conditions

[Scrumpy]

Hi, B3150 with genuine 4in1 bucket, low hours on unit. Was working fine but bucket wouldnt lift more than partway occasionally. not very often . BUT lately, bucket stops lifting fully after 6 or 7 lifts from cold, and wierdly, will only lift fully if I throttle back to idle, drop the bucket with the release hydraulics function (push control lever fully forward to let bucket drop by gravity), then I can lift bucket OK...until I increase revs then bucket will stop a bit under halfway up. straining noise as if hydraulics working but something holds it back. All other hydraulic functions are fine, recently serviced, drained hydraulic fluid and refilled with Genuine Kubota fluid, level is at top notch on the dipstick on transmission case at rear of tractor. Really strange - has anyone got any ideas please? Only way to reactivate lift function properly is as above, throttle back to idle, release bucket by gravity, then it works a treat. Hydraulic lines are Ok and have not been removed at all. And position of TPL control doesnt affect this problem.

 

[mikester]

Loose linkages on your joystick?

 

[GreensvilleJay]

Maybe 'junk' in the pressure release of the 'up-down' spool valve ?
Maybe the spring is broken ?
For sure remove whatever covers are there and SEE that proper range of joystick IS happening.

 

[North Idaho Wolfman]

Disconnect and reconnect all of the quick disconnects on the hydraulics, Including one behind the seat if equipped with a BH loop.

 

[Scrumpy]

Thanks everyone for your kind responses - been in hospital , hence delay.
Tonight I started tractor, lifted bucket no problems, went to the dirt pile (2 minutes) bucket wont lift - so it looks like the problem is getting worse, revs on engine or position of TPL makes no difference. Tried cracking hydraulic connections for "lift" at the actual rams as I couldnt get the quick connects to move (Im 66, replacement elbow joints so limited strength) - there seemed to be a heap of pressure come out but Im a hydraulic newby so I wouldnt know the difference!!! Ill try the advice re linkage but---if the lever works for a few times doesnt that rule out the linkage? sorry if that is a dopey question. Thanks in advance for any advice you can give.

 

[Russell King]

Thanks everyone for your kind responses - been in hospital , hence delay.
Tonight I started tractor, lifted bucket no problems, went to the dirt pile (2 minutes) bucket wont lift - so it looks like the problem is getting worse, revs on engine or position of TPL makes no difference. Tried cracking hydraulic connections for "lift" at the actual rams as I couldnt get the quick connects to move (Im 66, replacement elbow joints so limited strength) - there seemed to be a heap of pressure come out but Im a hydraulic newby so I wouldnt know the difference!!! Ill try the advice re linkage but---if the lever works for a few times doesnt that rule out the linkage? sorry if that is a dopey question. Thanks in advance for any advice you can give.

Did you read the post by @North Idaho Wolfman? Did you disconnect and re-connect the quick connects? since you state you are limited by elbow joint you might want to get someone else involved since they need to be well seated. Do them one at a time so you don’t get them accidentally connected in the wrong location.

And do all other functions on the bucket work correctly? Please verify.

If the other functions work properly, then switch lift hoses with the curl function and see if curl stops over time. Again mark the connection points and hoses so they can be returned to their original location.

 

[Scrumpy]

Hi, shed time! tractor in shed now. I read the Wolfman post, im currently removing the body work to get to the valve block under the 4 way lever. Ive got the seat off, and removed all the bolts for the vertical black panel between the seat platform and the floor - but cannot remove that panel because of the knob on the TPL lowering speed control. Any clues please? What are the adjustments for the bucket lifting linkage at the valve end of the 4way control lever?

 

[Scrumpy]

Update. Lowering Speed knob is simply a very tight press fit on this model so, with tha off, the panel cam off, access to the valve body. Ran the tractor, tried bucket lifting up and down, when it stopped lifting I tried gentle levering with a screwdriver under the valve linkage to make sure that the linkage was fully moving the valve. appeared to working properly.

 

[North Idaho Wolfman]

Update. Lowering Speed knob is simply a very tight press fit on this model so, with tha off, the panel cam off, access to the valve body. Ran the tractor, tried bucket lifting up and down, when it stopped lifting I tried gentle levering with a screwdriver under the valve linkage to make sure that the linkage was fully moving the valve. appeared to working properly.

You need to reread what I wrote as it has nothing to do with the valve it has to do with the quick connector or connectors on the loader hoses not the valve.
We don't have the b3150 in the USA so I can't give you a picture.

 

[North Idaho Wolfman]

Something similar to this:

 

[Scrumpy]

Hi Wolfman,
Thank you for your advice and help - I've raced cars and motorbikes all my life so Im handy around the shed but I have to admit since the elbow replacement I can do very fn'g little - very frustrating - I cannot do the quick releases, so Im going to have to pay my local hydraulic guy to come over and do the disconnect etc - Ill let you know how that goes. In the meantime, as I cant get out of the she due to the monsoon - so I thought Id try all the other suggestions re checking the valve body movement etc. with no improvement. Its very strange - after I start the tractor I can get 2 - 12 empty bucket lifts then it plays up. else if i try one laden lift it stops straight away - so I guess its a pressure issue, rather than a controller - would that be correct? again, thanks for your kind assistance and patience.

 

[PaulL]

Hi Wolfman,
Thank you for your advice and help - I've raced cars and motorbikes all my life so Im handy around the shed but I have to admit since the elbow replacement I can do very fn'g little - very frustrating - I cannot do the quick releases, so Im going to have to pay my local hydraulic guy to come over and do the disconnect etc - Ill let you know how that goes. In the meantime, as I cant get out of the she due to the monsoon - so I thought Id try all the other suggestions re checking the valve body movement etc. with no improvement. Its very strange - after I start the tractor I can get 2 - 12 empty bucket lifts then it plays up. else if i try one laden lift it stops straight away - so I guess its a pressure issue, rather than a controller - would that be correct? again, thanks for your kind assistance and patience.

It does sound like a seating issue or connection issue, or some random junk floating around that can float in and block stuff up. So cleaning all the connectors and reseating is great advice. Acknowledging your limitations, my best guess is the hydraulic guy will come out and reseat them all, it'll probably work, but if not, he'll probably be pretty good at sorting it.

 

[Scrumpy]

It does sound like a seating issue or connection issue, or some random junk floating around that can float in and block stuff up. So cleaning all the connectors and reseating is great advice. Acknowledging your limitations, my best guess is the hydraulic guy will come out and reseat them all, it'll probably work, but if not, he'll probably be pretty good at sorting it.

Hi PaulL,
Thanks for your reply, mate. Overnight the residual pressure dropped so this afternoon I was determined to not let this sh%t beat me and got the 2 up and down quick connects off - there was one or two tiny pieces of crud in there (1-1.5mm) so cleaned those out. couldn't do the other QCs as i was tearing nerves in my arm and had enough. Got 2 lifts with loaded bucket then it froze down again. So that could be an improvement. With pressure in the lines I am stuffed until tomorrow as far as releasing the QCs , so Ill have a go again tomorrow, and try to switch the lift and lower QCs (A & B, White and Yellow) - that should be a reasonable test , shouldnt it? I really appreciate the patience of the kind experts in this forum - Im 66 and pretty banged up after a misguided career as a motorcycle road racer but Ive always done everything for myself (building bikes, cars, engines , sheds etc) so with the help of this excellent forum Im determined to beat this tractor. You only really know equipment after you've pulled it apart, right???

 

[PaulL]

Do you have a wife, neighbour, child, random guy walking down the road, who'd unplug and replug them for you a few times? That'd make it way easier.

I'm trying to recall whether I saw a sort of tool that'd clip on and help disconnect pioneer couplings. I have a vague recollection of a fork thing with a lever, but no idea whether I'm imagining that or I saw one somewhere. I wonder if you could make a thing if you thought about it.

 

[Russell King]

Do you have a wife, neighbour, child, random guy walking down the road, who'd unplug and replug them for you a few times? That'd make it way easier.

I'm trying to recall whether I saw a sort of tool that'd clip on and help disconnect pioneer couplings. I have a vague recollection of a fork thing with a lever, but no idea whether I'm imagining that or I saw one somewhere. I wonder if you could make a thing if you thought about it.

I think this might be what you were thinking of?

XBoom Excavator Coupler System (Excavator Skid Steer Loader Adapter Coupler System)

@Scrumpy if you want you might want to replace the disconnects with something that might be easier for you to operate. There are some that screw together instead of the sleeve that has to slide back or you could just ditch the disconnects and attach the hose directly if you never intend to remove your FEL, or just make a small mess when you do remove it.

 

[PaulL]

I think this might be what you were thinking of?

XBoom Excavator Coupler System (Excavator Skid Steer Loader Adapter Coupler System)

Not quite. But did get me to do a google. I see a few threads talking about similar things:

https://forums.yesterdaystractors.com/threads/pioneer-coupler-tool.1561799/

Which has this picture in it, which may give some ideas:

Coupler connecting / disconnecting Tool

The coupler depressurize tools are different from the coupler attach/detach tools. Here's a thread with a nice simple to make attach/detach tool: https://www.tractorbynet.com/forums/hydraulics/406958-tool-hyd-coupling.html He made it for a 1/4" coupler. A 1/2" coupler may require more fab work...

www.tractorbynet.com

Then there's this thread, which says that you can get "push-pull" couplers - which I interpret as saying you can slide the sleeve either way. Combine that with one of those tools, and my impression is you could just use the tool to push the male into the female, and it will connect without holding the sleeve back. And same in the opposite direction - you can basically just pull the hose out, which the tool could do for you.

This thread: https://www.tractorbynet.com/forums/threads/tool-for-hyd-coupling.406958/ describes making a tool to hold the sleeve back. The extension I'd maybe make is that instead of using pliers, I'd use vice grips. Then it'd pull the sleeve back, and lock holding it. That'd give you time to remove or insert the male, then release the vice grips. Not sure if it would work, but seems to me it should.

 

[Scrumpy]

Man, you guys are awesome! Thanks for all the hints and tips, love the special tools - Ive always been fond of designing and building tools to make a job easier/safer. Update: I got the hydraulic guy to drop by - he couldn't work it out - he thought it might be leaking seals in a lift ram, allowing pressurisation of both sides - which doesn't sound right. we left the tractor with its wheels raised on the bucket arms fully down to see if the fluid drained back overnight - no movement. I also ran the problem past the local Darwin Kubota dealer and they said they'd never heard of this problem before. So I de-pressurised the lift and drop hoses (yellow and white), removed , checked - all clean, BUT.....I followed the earlier advice from a learned gentleman on this forum and switched them when i replaced them....Using the 4 way joystick in reverse the bucket then raised perfectly, but would not lower. - so...does that give any clues? When I reversed the hoses back to their proper positions I, again, got a few empty lifts Ok, but the first lift with 1/4 bucket of dirt stopped halfway. Thanks for your help - any further ideas of how to track this would be great - the local experts dont seem confident on what is wrong.

 

[Russell King]

I am not 100% sure what you did in your last test so you may want to give a full description of what it was doing before and what you swapped and what happened with the loader. I don’t think you left it “reversed” and used it to try and lift a bucket with weight in it. You might try that and clarify what you did and what happens. (You have to remember that we are reading this over days and our memory is not what it should be!)(and I am too lazy to look back very carefully)

But it really sounds like you have one bad coupling half. Since I am not smart enough to determine which half might be bad, I suggest you invest in one full coupling (male and female) that matches what you have on the tractor. Then on the line from the valve towards the cylinder(s) replace the full coupling on the line that doesn’t function properly (lift line or down line) and see if that make it function properly.

You could just eliminate the coupling if the hose can connect to the valve without the coupling installed. That depends on how it is currently arranged or what fittings you can obtain easily. I don’t think you have posted any pictures of your valve or couplers so I can’t really tell you much more than it is probably possible.

 

[Scrumpy]

I am not 100% sure what you did in your last test so you may want to give a full description of what it was doing before and what you swapped and what happened with the loader. I don’t think you left it “reversed” and used it to try and lift a bucket with weight in it. You might try that and clarify what you did and what happens. (You have to remember that we are reading this over days and our memory is not what it should be!)(and I am too lazy to look back very carefully)

But it really sounds like you have one bad coupling half. Since I am not smart enough to determine which half might be bad, I suggest you invest in one full coupling (male and female) that matches what you have on the tractor. Then on the line from the valve towards the cylinder(s) replace the full coupling on the line that doesn’t function properly (lift line or down line) and see if that make it function properly.

You could just eliminate the coupling if the hose can connect to the valve without the coupling installed. That depends on how it is currently arranged or what fittings you can obtain easily. I don’t think you have posted any pictures of your valve or couplers so I can’t really tell you much more than it is probably possible.
[/QUOTE
Many thanks mate,
Sorry it is taking a long while tpo try things but I get an hour a day at best to do shed things before its back on the couch and hte pain killers. So...Yesterday tried a few things...If the lift arms are left up overnight they eventually droop to the ground under their own weight - normal, I think? Tried disconnect yellow (lift) and white(drop) Quick Connects, checked, seemed clean. Reconnected them reversed, white (drop) from the lift arm to yellow (lift) on the 4 point connector. Yellow (lift) from lift arm to white (drop) on the 4pt connector. Operate 4 way joystick: Push forward (drop) LIFTS the loader arms, as expected. pull back (lift) should now drop loader but NOTHING happened except revs changed. To me this means the Rams and seals should be OK, both white and yellow circuits from the Quick Connects forward are OK. BUT yellow circuit from the Quick Connect rearwards is where the problem is. i.e. from QC marked "120" on the Hydraulic Loader pipe diagram posted in comments above. Im going to re-check the valve block at the 4way joystick is moving the valves (spools?) fully as it seems to have more travel on drop than raise.
Then I guess I start swapping bits between the yellow and white circuits untill the problem moves from yellow to white.

 

[Grandad4]

The experts here have all the knowledge and I can't add much to their good advice, but I noticed there a couple of things that haven't come up so far.
1. It is suspicious that the problems showed up just after service work was done. The big question is who did what ?
2. The 4 in 1 bucket will have a 3rd hydraulic circuit. Is it OK?
Best of luck sorting out this problem.