Hydraulic issue L45 bucket:

[Saturn]

Hello all,
My L45 front loader recently developed an issue where the bucket is very slow to dump.
All other functions of the loader work properly.
The oil is newer (about 150 hrs), full and clear. (Kubota oil).
I know nothing of hydraulics but looks like I'm about to learn?
I'm pretty mechanical and have a factory service manual.
Observations:
Cylinders and rods don't appear to be bent.
Cylinders not leaking fluid.
Is there anyway to tell if I have a faulty cylinder or valve or pump or whatever?
Thanks in advance for any assistance.
rob

 

[TheOldHokie]

Hello all,
My L45 front loader recently developed an issue where the bucket is very slow to dump.
All other functions of the loader work properly.
The oil is newer (about 150 hrs), full and clear. (Kubota oil).
I know nothing of hydraulics but looks like I'm about to learn?
I'm pretty mechanical and have a factory service manual.
Observations:
Cylinders and rods don't appear to be bent.
Cylinders not leaking fluid.
Is there anyway to tell if I have a faulty cylinder or valve or pump or whatever?
Thanks in advance for any assistance.
rob

Two obvious things to check:

1) Valve oil delivery is slow.
2) Exhaust oil flow is (partially) blocked

I am guessing (pretty good one) that your loader valve has regen on the extend function. That sort of rules out #2 but its easy to check. Just disconnect the rod end hose (not the coupler) at the loader valve and put it in a bucket. Start the machine and test dump. If its faster something is wrong on that side of the cylinder.

For #1 disconnect the base end hose at the bucket and dobs similar test to see if you arevgetting good flow from that side.

Dan

 

[Saturn]

Two obvious things to check:

1) Valve oil delivery is slow.
2) Exhaust oil flow is (partially) blocked

I am guessing (pretty good one) that your loader valve has regen on the extend function. That sort of rules out #2 but its easy to check. Just disconnect the rod end hose (not the coupler) at the loader valve and put it in a bucket. Start the machine and test dump. If its faster something is wrong on that side of the cylinder.

For #1 disconnect the base end hose at the bucket and dobs similar test to see if you arevgetting good flow from that side.

Dan

Two obvious things to check:

1) Valve oil delivery is slow.
2) Exhaust oil flow is (partially) blocked

I am guessing (pretty good one) that your loader valve has regen on the extend function. That sort of rules out #2 but its easy to check. Just disconnect the rod end hose (not the coupler) at the loader valve and put it in a bucket. Start the machine and test dump. If its faster something is wrong on that side of the cylinder.

For #1 disconnect the base end hose at the bucket and dobs similar test to see if you arevgetting good flow from that side.

Dan

Thanks Dan for your comment. I'll try your suggestion on Monday when I return to the farm.
The loader on the L45 is the TL1000. There are no quick disconnects.
It appears from the service manual that it does have regen. ( I had to look up what that meant) so I'll start with suggestion #1.
When you say disconnect the base end hose at the bucket do you mean remove one of the hoses from the bucket cylinder?
Sorry, I'm just learning hydraulic language.
Thanks again.
rob

 

[TheOldHokie]

Thanks Dan for your comment. I'll try your suggestion on Monday when I return to the farm.
The loader on the L45 is the TL1000. There are no quick disconnects.
It appears from the service manual that it does have regen. ( I had to look up what that meant) so I'll start with suggestion #1.
When you say disconnect the base end hose at the bucket do you mean remove one of the hoses from the bucket cylinder?
Sorry, I'm just learning hydraulic language.
Thanks again.
rob

Learning is good and you seem to have the knack.

No couplers reduces the variables and simplifies the situation. Personally I would start with the rod (outlet) end of the cylinders. That sort of gets at both possibilities in one step. Disconnect that hose at the loader valve and see if it makes any difference in speed.

Does the loader valve have a (possibly detented) position on extend? Something similar to the float position on the boom.

Dan

 

[fried1765]

Thanks Dan for your comment. I'll try your suggestion on Monday when I return to the farm.
The loader on the L45 is the TL1000. There are no quick disconnects.
It appears from the service manual that it does have regen. ( I had to look up what that meant) so I'll start with suggestion #1.
When you say disconnect the base end hose at the bucket do you mean remove one of the hoses from the bucket cylinder?
Sorry, I'm just learning hydraulic language.
Thanks again.
rob

The L45.... "does have regen" ?

 

[6869704x4]

The L45.... "does have regen" ?

Bought mine new in 2011, it does not have it.

 

[Russell King]

Just to clarify terms being asked about

The cylinder has a base end attached to the tractor. This is the end of the cylinder that is opposite the rod and usually doesn’t extend.

The rod end is obviously the other side of the cylinder that has the rod that is inside the cylinder base.

If it is installed “backwards” I don’t know what that does to the terminology since the rod end is now technically the base of the cylinder assembly!

 

[TheOldHokie]

Just to clarify terms being asked about

The cylinder has a base end attached to the tractor. This is the end of the cylinder that is opposite the rod and usually doesn’t extend.

The rod end is obviously the other side of the cylinder that has the rod that is inside the cylinder base.

If it is installed “backwards” I don’t know what that does to the terminology since the rod end is now technically the base of the cylinder assembly!

Dont over think this - it has nothing to do with how the cylinder is mounted. This is standard catalog priduct nomenclature. For single rod cylinders:

Rod end = end of cylinder from which the rod protrudes.

Base end = the other end of the cylinder

Nothing more, nothing less.

Dan

 

[fried1765]

Bought mine new in 2011, it does not have it.

OP says yes!
Is it possible that some later models do?

 

[TheOldHokie]

OP says yes!
Is it possible that some later models do?

Kubota mixed and mstched regen on many differrent models of their loaders. You have to check the individual valve to know.

Dsn

 

[Saturn]

My L45 is a 2011 model.
As I said in a previous post I'm just learning hydraulic language. (just learned to spell it)
When trying to determine if my machine had hydraulic regen, I searched online and found this definition:

What is a regen on a hydraulic system?

Regeneration is a general term that describes what happens when exhausting hydraulic fluid from the rod side of an actuator is directed back into the pressure line. The exhausting fluid is reused or regenerated to do work.

This is a description of the bucket dump hydraulics taken from the Kubota WSM page 10-M38:

The following explanations explain illustration figure 1,2,3 and 4. When the bucket spool (25) is pushed in, the hydraulic oil from P port (1) passes through the center by-pass passage (4) (Refer to the b-b.) via the load check valve (24) and is discharged into the opened A2 and 82 ports. As a result, the oil is supplied to the rod side and the bottom side of the bucket cylinder, and acts in the extending direction according to the cylinder area ratio. As the bucket cylinder extends, the oil in the rod side flows into the valve through A2 port, and joins the oil from P port (1) and is led to the bottom side again (Refer to the c-c.). During this operation, the oil is not discharged through P.B. port (26) and T porl (27). When the bucket cylinder extends and reaches the stroke end during operation of the dump, the tractor main relief valve operates and retains the pressure of P port (1) atthe set pressure by discharging hydraulic oilfrom the pump into the tank.

Does this description indicate that my machine has regen?
thanks
sorry for the long post:
rob

 

[Saturn]

My L45 is a 2011 model.
As I said in a previous post I'm just learning hydraulic language. (just learned to spell it)
When trying to determine if my machine had hydraulic regen, I searched online and found this definition:

What is a regen on a hydraulic system?

Regeneration is a general term that describes what happens when exhausting hydraulic fluid from the rod side of an actuator is directed back into the pressure line. The exhausting fluid is reused or regenerated to do work.

This is a description of the bucket dump hydraulics taken from the Kubota WSM page 10-M38:

The following explanations explain illustration figure 1,2,3 and 4. When the bucket spool (25) is pushed in, the hydraulic oil from P port (1) passes through the center by-pass passage (4) (Refer to the b-b.) via the load check valve (24) and is discharged into the opened A2 and 82 ports. As a result, the oil is supplied to the rod side and the bottom side of the bucket cylinder, and acts in the extending direction according to the cylinder area ratio. As the bucket cylinder extends, the oil in the rod side flows into the valve through A2 port, and joins the oil from P port (1) and is led to the bottom side again (Refer to the c-c.). During this operation, the oil is not discharged through P.B. port (26) and T porl (27). When the bucket cylinder extends and reaches the stroke end during operation of the dump, the tractor main relief valve operates and retains the pressure of P port (1) atthe set pressure by discharging hydraulic oilfrom the pump into the tank.

Does this description indicate that my machine has regen?
thanks
sorry for the long post:
rob

 

[TheOldHokie]

My L45 is a 2011 model.
As I said in a previous post I'm just learning hydraulic language. (just learned to spell it)
When trying to determine if my machine had hydraulic regen, I searched online and found this definition:

What is a regen on a hydraulic system?

Regeneration is a general term that describes what happens when exhausting hydraulic fluid from the rod side of an actuator is directed back into the pressure line. The exhausting fluid is reused or regenerated to do work.

This is a description of the bucket dump hydraulics taken from the Kubota WSM page 10-M38:

The following explanations explain illustration figure 1,2,3 and 4. When the bucket spool (25) is pushed in, the hydraulic oil from P port (1) passes through the center by-pass passage (4) (Refer to the b-b.) via the load check valve (24) and is discharged into the opened A2 and 82 ports. As a result, the oil is supplied to the rod side and the bottom side of the bucket cylinder, and acts in the extending direction according to the cylinder area ratio. As the bucket cylinder extends, the oil in the rod side flows into the valve through A2 port, and joins the oil from P port (1) and is led to the bottom side again (Refer to the c-c.). During this operation, the oil is not discharged through P.B. port (26) and T porl (27). When the bucket cylinder extends and reaches the stroke end during operation of the dump, the tractor main relief valve operates and retains the pressure of P port (1) atthe set pressure by discharging hydraulic oilfrom the pump into the tank.

Does this description indicate that my machine has regen?
thanks
sorry for the long post:
rob

Yes. The Readers Digest version:

Exhaust oil from the rod end is directed to the base end port where it combines with tje incoming pump flow. This results in an increase in the inflow to the base end and increases speed of rod extension. No oil flows to tank or power beyond. Additionally, because both sides of the piston are being equally pressurized, the actustor force is reduced to:

F = (pressure x cross sectional area of the rod)

Dan

 

[Saturn]

Thanks Dan

 

[Saturn]

Two obvious things to check:

1) Valve oil delivery is slow.
2) Exhaust oil flow is (partially) blocked

I am guessing (pretty good one) that your loader valve has regen on the extend function. That sort of rules out #2 but its easy to check. Just disconnect the rod end hose (not the coupler) at the loader valve and put it in a bucket. Start the machine and test dump. If its faster something is wrong on that side of the cylinder.

For #1 disconnect the base end hose at the bucket and dobs similar test to see if you arevgetting good flow from that side.

Dan

OK
I disconnected the base end hose and I got what I believed to be good flow.
The bucket still is slow to dump?
I tested both cylinders.
Same result.
Any ideas
thanks
rob

 

[TheOldHokie]

OK
I disconnected the base end hose and I got what I believed to be good flow.
The bucket still is slow to dump?
I tested both cylinders.
Same result.
Any ideas
thanks
rob

You jumped way ahead. I thought when you did the first test with the rod end hose disconnected the loader lifted fine. Is that correct or not?

Dan

 

[Saturn]

You jumped way ahead. I thought when you did the first test with the rod end hose disconnected the loader lifted fine. Is that correct or not?

Dan

the loader boom lifts and drops fine
the bucket curls fine
just slow to dump

 

[Saturn]

the loader boom lifts and drops fine
the bucket curls fine
just slow to dump

I didn't do the test labeled #2 because we determined that the machine had regen.
Should I do test #2 ?
Test #1 indicated what I think was good flow.

 

[TheOldHokie]

the loader boom lifts and drops fine
the bucket curls fine
just slow to dump

Are you saying that with everything hooked up as normal the only problem is slow dump?

Dan

 

[Saturn]

Are you saying that with everything hooked up as normal the only problem is slow dump?

Dan

that's exactly what I'm saying