3 Point works but not with a load

[Bradnsteph28]

I have a Kubota BF900 tractor. I unhooked the king kutter tiller a few months ago and everything was working. Yesterday I reattached and it won’t raise. The bucket and all other features work great with no issues. There is no leaks visible either. I then unhooked the tiller and raised the arms, they will raise but when I put my hand on them and cause any resistance, they stop. The valve under the seat from what I know is only for the speed of lowering. I played with all different positions on that, but that I don’t think is the issue. I’m lost and need to till my garden. Could it be the hydraulic filter, but the bucket works great. I don’t know if I have a diverted valve, but in the past I never had to do anything when using it. Any help would be great.

 

[fried1765]

I have a Kubota BF900 tractor. I unhooked the king kutter tiller a few months ago and everything was working. Yesterday I reattached and it won’t raise. The bucket and all other features work great with no issues. There is no leaks visible either. I then unhooked the tiller and raised the arms, they will raise but when I put my hand on them and cause any resistance, they stop. The valve under the seat from what I know is only for the speed of lowering. I played with all different positions on that, but that I don’t think is the issue. I’m lost and need to till my garden. Could it be the hydraulic filter, but the bucket works great. I don’t know if I have a diverted valve, but in the past I never had to do anything when using it. Any help would be great.

Seems to me that the hydraulic lift piston ring(s?) may be worn and bypassing fluid.
This is a common problem on 25 year, or older, tractors.
Yours is how old?

The fix is to replace the hydraulic piston ring, or rings.
This is not a particularly difficult repair.
If you need to do this, you may want to either put your piston in the freezer first, or put the new ring(s?) in boiling water first,..... or both.

 

[TheOldHokie]

I have a Kubota BF900 tractor. I unhooked the king kutter tiller a few months ago and everything was working. Yesterday I reattached and it won’t raise. The bucket and all other features work great with no issues. There is no leaks visible either. I then unhooked the tiller and raised the arms, they will raise but when I put my hand on them and cause any resistance, they stop. The valve under the seat from what I know is only for the speed of lowering. I played with all different positions on that, but that I don’t think is the issue. I’m lost and need to till my garden. Could it be the hydraulic filter, but the bucket works great. I don’t know if I have a diverted valve, but in the past I never had to do anything when using it. Any help would be great.

BF900??? I suspect that is the model of the liader not the trsctor.

In any event it sounds like this just started out of the blue and the loader valve is not supplying full pressure to the 3pt. Check any quick connects and pressure at the power beyond port on the loader valve.

Dan

 

[Bradnsteph28]

Here is a photo of the tractor

 

[Bradnsteph28]

Seems to me that the hydraulic lift piston ring(s?) may be worn and bypassing fluid.
This is a common problem on 25 year, or older, tractors.
Yours is how old?

The fix is to replace the hydraulic piston ring, or rings.
This is not a particularly difficult repair.
If you need to do this, you may want to either put your piston in the freezer first, or put the new ring(s?) in boiling water first,..... or both.

It is 25 years old plus . Where are those located? This was my father in laws who has passed. I’m very handy but never worked on hydraulics.

 

[Bradnsteph28]

BF900??? I suspect that is the model of the liader not the trsctor.

In any event it sounds like this just started out of the blue and the loader valve is not supplying full pressure to the 3pt. Check any quick connects and pressure at the power beyond port on the loader valve.

Dan

Ok. I am new to hydraulics , but handy.

 

[TheOldHokie]

Here is a photo of the tractor View attachment 99833

BF900 is the model number of the loader. Tractor model number is usually on the side of the hood. Its also on a data plate usually attached to the trsnsmission.

The BF900 loader has quick connects on the 3 hoses that connect the valve to the tractor. I suggest you check the one on the power beyond return hose. If its not fully connected your 3pt wont work.

Dan

 

[Bradnsteph28]

BF900 is the model number of the loader. Tractor model number is usually on the side of the hood. Its also on a data plate usually attached to the trsnsmission.

The BF900 loader has quick connects on the 3 hoses that connect the valve to the tractor. I suggest you check the one on the power beyond return hose. If its not fully connected your 3pt wont work.

Dan

Will do. I am not there, but you are right I believe it is an LS something. Will verify. I looked into the piston ring, I believe that is under the seat by the open and close valve. I bet that ring is bad. Is that housing piston on for the 3 point?

 

[Bradnsteph28]

Seems to me that the hydraulic lift piston ring(s?) may be worn and bypassing fluid.
This is a common problem on 25 year, or older, tractors.
Yours is how old?

The fix is to replace the hydraulic piston ring, or rings.
This is not a particularly difficult repair.
If you need to do this, you may want to either put your piston in the freezer first, or put the new ring(s?) in boiling water first,..... or both.

I watched some videos on replacing that. Looks fairly easy. Why would the bucket still work though? Also when I replace that , do I need to release pressure anywhere or is It not under pressure in that housing.

 

[TheOldHokie]

I watched some videos on replacing that. Looks fairly easy. Why would the bucket still work though? Also when I replace that , do I need to release pressure anywhere or is It not under pressure in that housing.

Lift pistons dont typically go south over night. Before you get carried away tearing things apart CHECK THE 3pt SUPPLY PRESSURE.

The loader works because it is the first device in the hydraulic circuit. The OUT side of the loader valve supplies pressure to the 3pt and if that connection is compromised the 3pt wont work. That is a COMMON problem. Spend $20 for a hydraulic pressure gauge and you can confirm the 3pt is getting full presdure from the loader. A pressure gauge is cheap and an essential tool when troubleshooting hydraulic systems.

Dan

 

[fried1765]

I watched some videos on replacing that. Looks fairly easy. Why would the bucket still work though? Also when I replace that , do I need to release pressure anywhere or is It not under pressure in that housing.

I have a 1989 Ford 1920 4x4 (a wonderful little 32 HP tractor)
I actually use my little Ford significantly more often than my much larger, and newer, HST Kubota.
The Ford three point hitch acted just as you describe,..... after sitting for a few months.
The loader continued to work just fine.

I do not know how Kubota creates their hydraulic systems, but on the Ford there is an internal 3pt lift cyl. (under the seat), that apparently operates only the 3pt. hitch.
Consulted my Ford WSM, and replaced that teflon piston seal, now 3pt. hitch works just fine.
You should consult your Kubota WSM for more information!
If you do not have the appropriate Kubota WSM, you should get one!

 

[TheOldHokie]

I do kno

I have a 1989 Ford 1920 4x4 (a wonderful little 32 HP tractor)
I actually use my little Ford much more often than my larger, and newer, Kubota
The Ford three point hitch acted just as you describe,..... after sitting for several months.
The loader continued to work just fine.

I do not know how Kubota creates their hydraulic systems, but on the Ford there is an internal 3pt lift cyl. (under the seat), that apparently operates only the 3pt. hitch.
Consulted my Ford WSM, and replaced that teflon piston seal, now 3pt. hitch works just fine.
You should consult your Kubota WSM for more information!
If you do not have the appropriate Kubota WSM, you should get one!

Will do. I am not there, but you are right I believe it is an LS something. Will verify. I looked into the piston ring, I believe that is under the seat by the open and close valve. I bet that ring is bad. Is that housing piston on for the 3 point?

Here is the hydraulic plumbing on your BF900 loader. I have labeled the quick connect that supplies hydraulic pressure to the 3pt. You can quickly and easily check pressure at that point BEFORE you take anything apart Simply unscrew the hose #10 from the male tip #20 and screw a 3000+ PSI pressure gauge into the male tip. Start the tractor and you should immediately get a pressure indication close to 2000 PSI.

If its only a few hundred pounds of pressure or less your problem is in the loader supply l;ine NOT the lift cylinder. The quick connector would be the next thing to suspect.

If you DO get 1500+ PSI pressure then reconnect the hose and retest the the lift to make sure you have not "fixed" the problem by simply messing with the coupler.

If and only if you can verify the 3pt is getting adequate pressure but the 3pt wont lift a load you can then turn your attention to the lift cylinder.

Dan

 

[North Idaho Wolfman]

I'd put my money on a feedback linkage that has come off.
or it's a model with draft.
Need to know the model of the tractor before we can move on.

 

[Mark_BX25D]

Lift pistons dont typically go south over night.

True, but they do sometimes take a quick trip to Vegas.

 

[Bradnsteph28]

I'd put my money on a feedback linkage that has come off.
or it's a model with draft.
Need to know the model of the tractor before we can move on.

the circle modeled number.

 

[North Idaho Wolfman]

Look at this link and make sure it's intact.

Check all of the linkage to the draft and the lift levers.
And try moving the draft lever along with the lift lever

 

[Bradnsteph28]

Look at this link and make sure it's intact.

View attachment 99884

Check all of the linkage to the draft and the lift levers.
And try moving the draft lever along with the lift lever

View attachment 99885

I will check tonight. Thank you for the diagram.

 

[fried1765]

True, but they do sometimes take a quick trip to Vegas.

Mine sure did.

 

[Bradnsteph28]

I do kno


Here is the hydraulic plumbing on your BF900 loader. I have labeled the quick connect that supplies hydraulic pressure to the 3pt. You can quickly and easily check pressure at that point BEFORE you take anything apart Simply unscrew the hose #10 from the male tip #20 and screw a 3000+ PSI pressure gauge into the male tip. Start the tractor and you should immediately get a pressure indication close to 2000 PSI.

If its only a few hundred pounds of pressure or less your problem is in the loader supply l;ine NOT the lift cylinder. The quick connector would be the next thing to suspect.

If you DO get 1500+ PSI pressure then reconnect the hose and retest the the lift to make sure you have not "fixed" the problem by simply messing with the coupler.

If and only if you can verify the 3pt is getting adequate pressure but the 3pt wont lift a load you can then turn your attention to the lift cylinder.

Dan

View attachment 99848

Does anyone have a link to an affordable/decent quality hydraulic pressure gauge that will fit this tractor to test the PSI?

 

[TheOldHokie]

Does anyone have a link to an affordable/decent quality hydraulic pressure gauge that will fit this tractor to test the PSI?

Sure. All you need for this test is a $15 3000 PSI gauge and an adapter fitting. If you want a real kit here is one. Probably Harbor Freight quality but I would buy it expecting it to do its job for decades.

https://a.co/d/8q3HjbW

It comes with 3 BSPP test points but nothing NPT so you would also need a BSPP female to NPT male adapter to hook it to your quick coupler.

Dan