Loader Getting Weak With Use?

[TheOldHokie]

Guage setup if anyone is interested.

I really dont know what you are actually measuring with that gauge setup. What are you trying to measure?

Dsn

 

[Soopitup]

I really dont know what you are actually measuring with that gauge setup. What are you trying to measure?

Dsn

In line working pressure.
That tees into any coupling connection so I can read the pressure as the system is running and working.

 

[TheOldHokie]

In line working pressure.
That tees into any coupling connection so I can read the pressure as the system is running and working.

That does not tell you much since you have no way of knowing whats producing or reducing pressure.

If you think the loader is weak you need to isolate and measure loader inlet pressure followed by work circuit pressure:

1. Remove inlet supply hose from loader valve and connect gauge to end of hose. Start tractor abd read pressire. That is what is available to the loader and should be msximum system pressure as listed in WSM.
2. Reconnect inlet hose and connect gauge to any work port on the loader. Start tractor and operate loader valve to pressurize the work port. It should be same as inlet pressure.

If you do not get max system pressure at inlet sonething is wrong upstream of the loader valve.

If you get max system presdure at inlet but not work port the relief valve (if any) in the loader valve is set too low.

If you get max pressure at both points there is nothing wrong with the system.

Dan

 

[Soopitup]

To clarify, I have that setup because it allows me to either check as a tee or as an end (male or female only into a fitting, which works the same as your gauge setup). Dual purpose.

I have the WSM, but not in front of me (I have the free fuzzy diagram version, I'm probably going to have to get a good one at some point).

In the meantime, I believe the backhoe power beyond (which is what I teed into and also checked with the hose disconnected) feeds the loader valve.
If that's the case the loader valve is only seeing the pressures I recorded.
I do need to go back and check the feed for the backhoe and see if it's getting the same pressures, I didn't have time tonight to do that.
If I had seen normal pressure at the backhoe power beyond my next step would have been to pull the loader manifold and check pressures there instead of going to the backhoe feed.

That does not tell you much since you have no way of knowing whats producing or reducing pressure.

Plugging that into the system gave me a very quick confirmation that there is a problem.
That was all I was initially looking for. I didn't have time to track the problem down tonight.

I understand what you're saying about teeing into the system not being able to isolate particular parts of the system; this is also a learning experience for me.
I learn best when I can see the system working.

 

[TheOldHokie]

To clarify, I have that setup because it allows me to either check as a tee or as an end (male or female only into a fitting, which works the same as your gauge setup). Dual purpose.

I have the WSM, but not in front of me (I have the free fuzzy diagram version, I'm probably going to have to get a good one at some point).

In the meantime, I believe the backhoe power beyond (which is what I teed into and also checked with the hose disconnected) feeds the loader valve.
If that's the case the loader valve is only seeing the pressures I recorded.
I do need to go back and check the feed for the backhoe and see if it's getting the same pressures, I didn't have time tonight to do that.
If I had seen normal pressure at the backhoe power beyond my next step would have been to pull the loader manifold and check pressures there instead of going to the backhoe feed.




Plugging that into the system gave me a very quick confirmation that there is a problem.
That was all I was initially looking for. I didn't have time to track the problem down tonight.

I understand what you're saying about teeing into the system not being able to isolate particular parts of the system; this is also a learning experience for me.
I learn best when I can see the system working.

You missed my point. I think I do understand how the system works. What I dont know is what you are measuring with that rig so that 1600 PSI number does not tell me there is or isnt a problem. Ir may be perfectly normal.

Can you draw a block diagram showing pump, loader valve, backhoe vakve, 3pt valve, tank, and where that gauge is in the circuit?

I will give you mine tomorrow.

Dan

 

[Soopitup]

I measured the backhoe power beyond output.
I disconnected the hose from the tractor and measured the pressure at the hose end.

I'm not able to do that tonight, but I'll try in the next day or two.

 

[TheOldHokie]

I measured the backhoe power beyond output.
I disconnected the hose from the tractor and measured the pressure at the hose end.

I'm not able to do that tonight, but I'll try in the next day or two.

Here is a block diagram of what you have now, With the gauge connected in that fashion you do not know where your "missing" pressure is going or what it is doing.

Dan

 

[ruger1980]

I believe @Soopitup is measuring at the point circled below. This would be enroute to the loader valve but after or with the BH valve in the circuit. I would recommend bypassing the BH valve to eliminate that from the equation. If the BH valve has it's own internal relief it can lower the max pressure setting for anything in the circuit after the valve.

 

[TheOldHokie]

I believe @Soopitup is measuring at the point circled below. This would be enroute to the loader valve but after or with the BH valve in the circuit. I would recommend bypassing the BH valve to eliminate that from the equation. If the BH valve has it's own internal relief it can lower the max pressure setting for anything in the circuit after the valve.

View attachment 125982

Unfortunately that schematic does not include the backhoe valve. You have to go down to the backhoe section of the manual to see that circuit and mentslly paste it into the overall diagram.

Dan

 

[ruger1980]

Yes and it does not have a main relief so I doubt the issue would lie with the BH valve itself. More likely a pump or flow priority valve issue.
That is if the low pressures he is seeing are in all functions and direction on the loader circuit.

 

[TheOldHokie]

Yes and it does not have a main relief so I doubt the issue would lie with the BH valve itself. More likely a pump or flow priority valve issue.
That is if the low pressures he is seeing are in all functions and direction on the loader circuit.

Or potentially the loader inlet relief. Thats why you need to isolate the circuit components and test in a structured fashion. Given the data so far we don't even know there is a problem. This machine only has 50 odd hours on it.....

Dan

 

[ruger1980]

I agree that it may not have an issue and it could be operator perception. But the schematic does not show a relief valve incorporated into the loader valve. I see the main relief in the pump as the sole protection for the circuit.

 

[TheOldHokie]

I agree that it may not have an issue and it could be operator perception. But the schematic does not show a relief valve incorporated into the loader valve. I see the main relief in the pump as the sole protection for the circuit.

Could well be just one relief assuming the OP has not added anything. That primary relief protects the pump and actually makes testing easier. Too bad Kubota did not do that on all of their tractors....

Dan

 

[Soopitup]

Much easier to do this on the laptop!

Here is a block diagram of what you have now, With the gauge connected in that fashion you do not know where your "missing" pressure is going or what it is doing.

Dan

View attachment 125981

Yes, that's what I have. I couldn't find an actual diagram anywhere, including the manual.
After reading through the hydraulic, backhoe, and loader sections that's what I came up with. Good to know I was right. You also have the gauge in the correct spot.
There is one addition, which shouldn't matter.
I have a Land Pride third function kit plumbed in between the loader valve and the 3 point. I don't remember exactly how its plumbed off the top of my head, but I know it's done correctly to the directions.

The power beyond hose between the backhoe and the loader valve has a flat face coupler connection. I believe the male fitting is on the backhoe side and the female on the tractor side (to the loader valve). I inserted my tee/gauge to this connection.

I did a bunch of checks with my gauge setup teed into the system where you have shown. I understand those are useless to you.

-I also checked with the backhoe power beyond disconnected and the gauge attached to the hose. I only did idle and max, got the same readings.

What I also did (and posted in the thread, you missed that part ) is disconnect the power beyond hose at the connection, and left my guage setup connected to the backhoe side. Eliminating everything after the backhoe.
I only checked pressure at idle and max while hot. But I got the same measurements.
600 PSI @ idle
1690 PSI @ max rpm

This machine only has 50 odd hours on it.....

125 hours as of last night.

Unless I'm wrong the next step is to disconnect the backhoe and check the pressure at the outlet hose from the pump/relief valve (with the hose disconnected from the loader valve).

 

[ruger1980]

Have you checked cycle times when hot yet? If not check them cold and then hot. Use a stop watch, time 3 cycles each function and direction and save the average. The specs are in the WSM. This will tell you if you have enough flow to the loader valve. You can bypass the BH valve to eliminate that , but I doubt that is the issue.

Remember you have a system that prioritizes a portion of flow to the steering valve. At idle where pump output is low you may not see enough flow to produce the results you are expecting.

 

[TheOldHokie]

Much easier to do this on the laptop!



Yes, that's what I have. I couldn't find an actual diagram anywhere, including the manual.
After reading through the hydraulic, backhoe, and loader sections that's what I came up with. Good to know I was right. You also have the gauge in the correct spot.
There is one addition, which shouldn't matter.
I have a Land Pride third function kit plumbed in between the loader valve and the 3 point. I don't remember exactly how its plumbed off the top of my head, but I know it's done correctly to the directions.

The power beyond hose between the backhoe and the loader valve has a flat face coupler connection. I believe the male fitting is on the backhoe side and the female on the tractor side (to the loader valve). I inserted my tee/gauge to this connection.

I did a bunch of checks with my gauge setup teed into the system where you have shown. I understand those are useless to you.



What I also did (and posted in the thread, you missed that part ) is disconnect the power beyond hose at the connection, and left my guage setup connected to the backhoe side. Eliminating everything after the backhoe.
I only checked pressure at idle and max while hot. But I got the same measurements.
600 PSI @ idle
1690 PSI @ max rpm




125 hours as of last night.

Unless I'm wrong the next step is to disconnect the backhoe and check the pressure at the outlet hose from the pump/relief valve (with the hose disconnected from the loader valve).

Put the gauge directly on the outlet for the backhoe. Nothing connected beyond that including the backhoe. You should get max sytem pressure at all engine RPMs includung idle. If not the relief valve or the pump is hosed.

If pressure is low (600 PSI) and goes up with RPM my guess is some debris lodged in the relieve valve.

Dan

 

[DustyRusty]

I just checked my 2019 BX23S with the loader and the backhoe off the tractor with the engine at normal operating temperature. At idle, (1200 RPM) I have 1500 PSI on a 3000 PSI oil-filled gauge. At loader/backhoe speed (2500 RPM) it jumps to 1650 PSI. At maximum throttle (3500 RPM) the reading goes to 1725 PSI. I have the shims to increase it and will probably do it sometime in the future but it isn't a high priority.

 

[TheOldHokie]

I just checked my 2019 BX23S with the loader and the backhoe off the tractor with the engine at normal operating temperature. At idle, (1200 RPM) I have 1500 PSI on a 3000 PSI oil-filled gauge. At loader/backhoe speed (2500 RPM) it jumps to 1650 PSI. At maximum throttle (3500 RPM) the reading goes to 1725 PSI. I have the shims to increase it and will probably do it sometime in the future but it isn't a high priority.

The WSM says 1780 to 1840 PSI so pretty close as is.

Dan

 

[GeoHorn]

YAWwwwnnnnn……

 

[Soopitup]

Hot fluid pump output. Same numbers as before.
600 PSI at idle
1700 PSI at full throttle (the relief valve was really screaming).

Cold pressure was a little higher than before though. I had something like 1400 PSI at idle.

I think I'll pull that relief valve for starters. See what it looks like in there.
I may toss a washer or two, see how much it raises the idle pressure.