Weak Hydraulics L245

[mleo]

I have an L245. The hydraulics are functioning but weaker than they should be. I've checked the fluid and replaced the filter. The problem is worse if the 3 point lift it raised all the way up. Don't know if that means anything. There's a box grader on there almost always. Lowering the grader a few inches from full up keeps the front loader working. If the 3 point is up all the way, the front bucket gets weaker and weaker until I can't even get it off the ground. Let the tractor sit a couple hours with everything down and the front functions again. I suspect air is getting in somewhere.

Could the PTO system be involved? There is nothing attached to the PTO, but I'm wondering if power is being diverted to the PTO drive anyway?

I'm just guessing right now. What are the troubleshooting steps do I need to take to figure out what the problem could be?

 

[TheOldHokie]

I have an L245. The hydraulics are functioning but weaker than they should be. I've checked the fluid and replaced the filter. The problem is worse if the 3 point lift it raised all the way up. Don't know if that means anything. There's a box grader on there almost always. Lowering the grader a few inches from full up keeps the front loader working. If the 3 point is up all the way, the front bucket gets weaker and weaker until I can't even get it off the ground. Let the tractor sit a couple hours with everything down and the front functions again. I suspect air is getting in somewhere.

Could the PTO system be involved? There is nothing attached to the PTO, but I'm wondering if power is being diverted to the PTO drive anyway?

I'm just guessing right now. What are the troubleshooting steps do I need to take to figure out what the problem could be?

If you dont already have a copy of the WSM download it here.

https://www.kubotabooks.com/AutoIndex/index.php?dir=Tractor%20Owners%20Manuals/&file=L185_l235_l245_l275_l285_l295_l305_l345_l355%20shop%20manual.pdf

The loss of loader function when the 3pt is raised is caused by an improperly adjusted lift linkage. The 3pt control valve is not shutting off when the arms get to the top of travel. The adjustment is a threaded "feedback" rod and jam nuts on the top left of the lift cover. See Par 118 and Figure 256 in the WSM for the details. Basically you need to loosen the nuts and adjust them to lengthen the rod. EZ-PZ.

If the loader is still weak after adjusting the feedback linkage you need to do some pressure testing.

Dan

 

[PoTreeBoy]

I have an L245. The hydraulics are functioning but weaker than they should be. I've checked the fluid and replaced the filter. The problem is worse if the 3 point lift it raised all the way up. Don't know if that means anything. There's a box grader on there almost always. Lowering the grader a few inches from full up keeps the front loader working. If the 3 point is up all the way, the front bucket gets weaker and weaker until I can't even get it off the ground. Let the tractor sit a couple hours with everything down and the front functions again. I suspect air is getting in somewhere.

Could the PTO system be involved? There is nothing attached to the PTO, but I'm wondering if power is being diverted to the PTO drive anyway?

I'm just guessing right now. What are the troubleshooting steps do I need to take to figure out what the problem could be?

No PTO involvement. Probably no air.

First, you need to adjust the feedback rod shown in this figure from the WSM @ Kubota books. OK, it's 3 am so you get the long version. Unlike your loader, the 3ph valve is not directly controlled by the control lever. There is a teeter-totter arrangement (control rod 11 in the figure) that controls the valve. The control lever sets the desired position by moving one end of the rod. The feedback linkage 'tells' the other end where the 3ph position actually is. Unless the two ends move an equal distance in opposite directions, the center of the rod moves, moving the valve stem with it. This causes the lift cylinder to rise or fall until balance is restored.

The problem occurs when balance can't be restored. There is, obviously, a limit to how high the hitch can lift. If the balance is still calling for lift when the cylinder (piston, actually) reaches its physical limit, the hydraulic pressure rises until the relief valve opens. So the feedback rod needs to be adjusted to prevent this condition (you've been 'adjusting' the other end of the control rod by lowering the lever).

The reason this affects your loader: the hydraulic system uses what's referred to as an 'open center' scheme. This puts all the users, boom cylinders, bucket cylinders and 3 pt cylinder, in series when they call for oil flow. Normally, the 3ph wouldn't be calling for flow while the loader is, but with the feedback misadjusted, it is constantly demanding flow. This imposes back pressure on the loader, leaving it little ability to do work. It also causes additional load on the engine, wasting fuel and heating up the hydraulic fluid.

After you've made this adjustment, come back for more sage advice if the lift still seems to be weak .

 

[TheOldHokie]

No PTO involvement. Probably no air.

First, you need to adjust the feedback rod shown in this figure from the WSM @ Kubota books. OK, it's 3 am so you get the long version. Unlike your loader, the 3ph valve is not directly controlled by the control lever. There is a teeter-totter arrangement (control rod 11 in the figure) that controls the valve. The control lever sets the desired position by moving one end of the rod. The feedback linkage 'tells' the other end where the 3ph position actually is. Unless the two ends move an equal distance in opposite directions, the center of the rod moves, moving the valve stem with it. This causes the lift cylinder to rise or fall until balance is restored.

View attachment 139142
The problem occurs when balance can't be restored. There is, obviously, a limit to how high the hitch can lift. If the balance is still calling for lift when the cylinder (piston, actually) reaches its physical limit, the hydraulic pressure rises until the relief valve opens. So the feedback rod needs to be adjusted to prevent this condition (you've been 'adjusting' the other end of the control rod by lowering the lever).

The reason this affects your loader: the hydraulic system uses what's referred to as an 'open center' scheme. This puts all the users, boom cylinders, bucket cylinders and 3 pt cylinder, in series when they call for oil flow. Normally, the 3ph wouldn't be calling for flow while the loader is, but with the feedback misadjusted, it is constantly demanding flow. This imposes back pressure on the loader, leaving it little ability to do work. It also causes additional load on the engine, wasting fuel and heating up the hydraulic fluid.

After you've made this adjustment, come back for more sage advice if the lift still seems to be weak .

I see you are an early riser too

Dan

 

[PoTreeBoy]

I see you are an early riser too

Dan

Sometimes I sleep in shifts. Getting old can be weird.

 

[TheOldHokie]

Sometimes I sleep in shifts. Getting old can be weird.

I understand not getting old is even wierder