Loader won't lower unless I use FLOAT

[jimwarneke]

Hello! New to the forums and new to Kubotas!

I recently aquired an old Kubota B7500 with a L272 loader and a RCK60 belly mower (with user manuals, parts lists, and WSMs for each).
It is new to me, but in very used condition. I have been going through it an making everything work properly using YouTube and my manuals but I am stuck on what to look for on the loader.

It will go up, dump, and curl with no issues - but the only way to make it lower is to push the control up into float mode and release the pressure. This makes it usable, but there is no down pressure for back grading.

I have done a complete hydraulic fluid change with all new filters. There are no leaks.

Ideas?

Any help given is greatly appreciated!

-Jim

 

[jimh406]

Must the loader valve attached to the control. I’d try taking it apart and clean it. Maybe it has a bit of rust or debris in it.

 

[TheOldHokie]

Hello! New to the forums and new to Kubotas!

I recently aquired an old Kubota B7500 with a L272 loader and a RCK60 belly mower (with user manuals, parts lists, and WSMs for each).
It is new to me, but in very used condition. I have been going through it an making everything work properly using YouTube and my manuals but I am stuck on what to look for on the loader.

It will go up, dump, and curl with no issues - but the only way to make it lower is to push the control up into float mode and release the pressure. This makes it usable, but there is no down pressure for back grading.

I have done a complete hydraulic fluid change with all new filters. There are no leaks.

Ideas?

Any help given is greatly appreciated!

-Jim

L272 is not a model number I recognize.

Is the loader powered by the tractor hydraulucs or does it have its own pump on the front of the tractor?

Dan

 

[Dustball]

L272 is not a model number I recognize.

Is the loader powered by the tractor hydraulucs or does it have its own pump on the front of the tractor?

Dan

I'm guessing he meant the LA272.

 

[TheOldHokie]

Hello! New to the forums and new to Kubotas!

I recently aquired an old Kubota B7500 with a L272 loader and a RCK60 belly mower (with user manuals, parts lists, and WSMs for each).
It is new to me, but in very used condition. I have been going through it an making everything work properly using YouTube and my manuals but I am stuck on what to look for on the loader.

It will go up, dump, and curl with no issues - but the only way to make it lower is to push the control up into float mode and release the pressure. This makes it usable, but there is no down pressure for back grading.

I have done a complete hydraulic fluid change with all new filters. There are no leaks.

Ideas?

Any help given is greatly appreciated!

-Jim

OK looks like the loader is probably an LA272.

A very common cause of your symptoms is a blocked power beyond circuit. No quick couplers on your machine so we can rule that possibility out. Lower the 3pt all the way down and see if you get normal loader operation.

Dan

 

[TheOldHokie]

I'm guessing he meant the LA272.

Thanks - just found it a minute ago.

Dan

 

[jimwarneke]

Thanks - just found it a minute ago.

Dan

Yes - I miss-typed the loader model. It is a LA272.

These diagrams are from the WSM, but I am at a loss.
There are 4 ports on the control, with 4 quick-disconnects to the loader (it's a quick remove type).

I did visually inspect the couplers, but didn't see anything obvious.

 

[TheOldHokie]

Yes - I miss-typed the loader model. It is a LA272.

These diagrams are from the WSM, but I am at a loss.
There are 4 ports on the control, with 4 quick-disconnects to the loader (it's a quick remove type).

I did visually inspect the couplers, but didn't see anything obvious.

View attachment 138839

View attachment 138840

I am talking about the three hoses that connect the valve to the tractor. No quick connects on them. Power beyond is the port labeled PB on your WSM diagram. The hose connected to it goes to an inlet/outlet block on the tractor.

Fully lowering the 3pt control lever is a really simple check - try that first.

Dan

 

[jimwarneke]

I am talking about the three hoses that connect the valve to the tractor. No quick connects on them. Power beyond is the port labeled PB on your WSM diagram. The hose connected to it goes to an inlet/outlet block on the tractor.

Fully lowering the 3pt control lever is a really simple check - try that first.

Dan

I will try that in the morning - Thanks Dan!

 

[mendonsy]

I recall reading a thread a couple of months ago with a similar problem. The result was that the 3 point lever was not in the center position causing the return line to be closed. i searched for that thread but was unable to find it.

 

[TheOldHokie]

I recall reading a thread a couple of months ago with a similar problem. The result was that the 3 point lever was not in the center position causing the return line to be closed. i searched for that thread but was unable to find it.

Its a common issue and there are dozens of those threads. Also ones involving a ui c k coupkers, rear remotes and back hoes.

Dan

 

[jimwarneke]

Thank you everyone for the help!

Dan- I started it up this morning, dropped the 3 point and to my surprise the bucket worked as expected!

After reading mendonsy's post - are you telling me the 3-point lever needs to be in a certain position for the loader to work? I know it's been up all of the time because I have a back blade on it for balance.

 

[TheOldHokie]

Thank you everyone for the help!

Dan- I started it up this morning, dropped the 3 point and to my surprise the bucket worked as expected!

After reading mendonsy's post - are you telling me the 3-point lever needs to be in a certain position for the loader to work? I know it's been up all of the time because I have a back blade on it for balance.

Well thats very good news. Simple and easy to fix..

The 3pt has a feedback linkage that is supposed to bump the 3pt valve back to the neutral position when the arms get to top of travel. Your feedback linkage appears to be out of adjustment and the valve is not shutting off at full lift . The WSM contains the procedure for adjusting the linkage. Nothing more than a threaded rod with a couple lock nuts.

Dan

 

[jimwarneke]

Well thats very good news. Simple and easy to fix..

The 3pt has a feedback linkage that is supposed to bump the 3pt valve back to the neutral position when the arms get to top of travel. Your feedback linkage appears to be out of adjustment and the valve is not shutting off at full lift . The WSM contains the procedure for adjusting the linkage. Nothing more than a threaded rod with a couple lock nuts.

Dan

Thanks!
I will look into that!

 

[Henro]

Thanks!
I will look into that!

Just an FYI, in case you don’t have the workshop manual. You can download the manual for the B 2710/B 2910 at kubotabooks.com. The 7800 is covered in an appendix at the back of the manual I referenced. Most of the B7800 is mechanically the same as the B2710/2910 I believe. So that manual should give you everything you need if you don’t already have it..