Trouble Shooting FEL B2601

[B2601WH]

You have got me totally confused as to how the tractor is configured.
Please answer the following one by one.

1. Is this a BH70 backhoe? If not what is it?
2. Is the backhoe mounted or not?
3. If it is mounted how are the 3pt arms still on the tractor?
4. If it is mounted is it connected to all three hydraulic outlets?

Now back to the front loader. You have more than enough pressure to raise a load. Lets just talk about the loader valve. Connect a plain hose to the backhoe power beyond outlet and stick the other end in the transmission filler. That isolates the loader from all of the other hydraulics. Now start the tractor - there should be a steady stream of oil coming out of that hose and back into the transmssion. Now test all loader functions and report your results. Just that - nothing more please.

Dan

I appreciate your patience Dan, I am obviously out of my expertise...

1. Yes, BH70
2. Yes, physically mounted and plumbed/connected. Disconnected to Test FEL
3. NA
4. Yes, all three

No steady stream of hydraulic fluid, not even a dribble
To make sure, I disconnected quick connect, hose to hose.

I apologize, My bad on 3ph, I should have said I have an under belly mower. Which the lift arms from the 3ph hitch control the height of the mower deck. I DO NOT have the mower deck connected. However, the mower, rear linkage is now in the DOWN position (like the 3ph arms) inches from the ground. Will not go up.

 

[Vigo]

So i edited my power beyond statements to say tank instead because i THINK i was understanding the flow through the system incorrectly. I don't think there should be ANY flow out of the power beyond port when a loader valve is pulled, regardless of whether a piston seal is leaking or not. Only a leak across the bore of the pulled loader valve should put fluid out the power beyond port when loader valve is pulled. I tried to catch my mistakes before posting but edited to correct them. Assuming im even right now!

If the power beyond port from the loader valve were blocked, the backhoe would never work.

If the 'exhausting' side of a lift cylinder were to have a blocked hose (pinched maybe) it probably wouldn't move much in either direction and putting the loader valve in float wouldn't necessarily let it move.

As far as the regen bucket spool, I know a bit about what regen is but don't know how to tell if a loader valve has it. But i do know that unless you have a bucket circuit with float, you can't put the loader cylinders in float while also being hooked to a regen bucket circuit that doesn't have float.

I agree that the next step is testing but looking at the clues available narrows down what/where/how to test. If we can rule things out from the symptoms then we don't have to test them.

 

[TheOldHokie]

So i edited my power beyond statements to say tank instead because i THINK i was understanding the flow through the system incorrectly. I don't think there should be ANY flow out of the power beyond port when a loader valve is pulled, regardless of whether a piston seal is leaking or not. Only a leak across the bore of the pulled loader valve should put fluid out the power beyond port when loader valve is pulled. I tried to catch my mistakes before posting but edited to correct them. Assuming im even right now!

If the power beyond port from the loader valve were blocked, the backhoe would never work.

If the 'exhausting' side of a lift cylinder were to have a blocked hose (pinched maybe) it probably wouldn't move much in either direction and putting the loader valve in float wouldn't necessarily let it move.

As far as the regen bucket spool, I know a bit about what regen is but don't know how to tell if a loader valve has it. But i do know that unless you have a bucket circuit with float, you can't put the loader cylinders in float while also being hooked to a regen bucket circuit that doesn't have float.

I agree that the next step is testing but looking at the clues available narrows down what/where/how to test. If we can rule things out from the symptoms then we don't have to test them.

Now we are making progress and I am not suspecting a kinked hose - rather a miss-connection. Your analysis is based on a couple false premises and bad assumptions which is why we are going step by tiny step.

First a quick explanantion of how the lift spool on Kubota loader valves work:

1. UP routes pressurized oil to the base end of teh cylinders and connects the rod end to the power beyond (open center) core in the valve. That exhaust oil goes then through the bucket spool and out the power beyond port
2. DOWN does the same thing in reverse
3. FLOAT connects pump and both lift cylinder work ports to TANK not power beyond and there is no pressure available to the bucket spool.
4. If the bucket spool is shifted to curl (not dump) at the same time as the lift spool is shifted to DOWN the oil goes to the rod end of the lift cylinder, the exhaust oil from those cylinders goes to the power beyond core where the bucket spool directs it to the rod end of the bucket cylinder, and finally bucket exhaust oil goes to TANK not power beyond

So the next thing to test is to try to lower the loader and when it stalls simultaneously move the joystick lever to bucket curl. Now if everything is connected correctly exhaust oil is going to tank. If the bucket starts to curl and the loader starts to lower we know the problem is in the PB circuit somewhere. There are still a number of possibilties to eliminate but we are gaining knowledge.

Dan

 

[TheOldHokie]

I appreciate your patience Dan, I am obviously out of my expertise...

1. Yes, BH70
2. Yes, physically mounted and plumbed/connected. Disconnected to Test FEL
3. NA
4. Yes, all three

No steady stream of hydraulic fluid, not even a dribble
To make sure, I disconnected quick connect, hose to hose.

I apologize, My bad on 3ph, I should have said I have an under belly mower. Which the lift arms from the 3ph hitch control the height of the mower deck. I DO NOT have the mower deck connected. However, the mower, rear linkage is now in the DOWN position (like the 3ph arms) inches from the ground. Will not go up.

Whoops - I got Vigo's repsonse confused with yours.

No oil out the power beyond with engine running means something is badly fubared. Time to start tracing hoses and verifyng connections. Were exactly did you disconnect the power beyond hose and are you sure it was power beyond and not tank? It might be time for some pictures of the hoses you are connecting and disconnecting.

Dan

 

[B2601WH]

Whoops - I got Vigo's repsonse confused with yours.

No oil out the power beyond with engine running means something is badly fubared. Time to start tracing hoses and verifyng connections. Were exactly did you disconnect the power beyond hose and are you sure it was power beyond and not tank? It might be time for some pictures of the hoses you are connecting and disconnecting.

Dan

 

[B2601WH]

Red TRACTOR outlet pipe is where connected pressure gauge.

Yellow BACKHOE power beyond HOSE is where I attached hose to see if their was fluid flow.

As I'm typing; should have I tested flow from yellow TRACTOR power beyond hose?

 

[TheOldHokie]

Red TRACTOR outlet pipe is where connected pressure gauge.

Yellow BACKHOE power beyond HOSE is where I attached hose to see if their was fluid flow.

As I'm typing; should have I tested flow from yellow TRACTOR power beyond hose?

We are slowly clearing up the confusion. I wanted you to check for flow at the same place as you connected the gauge.

Using your color ID scheme:

RED is the loader's power beyond outlet. That is where we need to check for flow. With the engine running there should be a constant flow of oill coming out of that point so you need to disconnect it and stick the end in the transmission filler so you don't pump the tractor dry while running the test.

That will completely disconnect the loader from the back hoe and 3pt. Then start the tractor and verify there is flow. If you got pressure at that connection there is almost surely going to be flow. Now run the loader through all functions. Everything should work and the only time that flow should ever stop is when you put the loader in FLOAT, or curl, or dump the bucket.

BTW - after all of this I am about 90% sure I know where the problem is, My educated guess is the power beyond conenction FROM the backhoe TO the tractor 3pt is blocked in some way. My analysis based on observed behaviors as I now understand them to be:

• The loader lift and power down won't work because it retruns exhaust oil to tank via the (presumably blocked) power beyond loop through the backhoe and 3pt.
• The loader lowers in FLOAT because pump and both cylinder ports are connected directly to tank via the return line on the loader valve.
• The bucket works because REGEN does not need a return and regular mode dump and curl both dump exhaust oil via the tank return port on the loader valve.
• The backhoe works because all of those BH70 spools dump exhaust oil straight to the tractor tank via the BLUE line
• The 3pt does not work because its supply of pressurized oil FROM the YELLOW backhoe power beyond outlet is (presumably) blocked.

Dan

 

[B2601WH]

We are slowly clearing up the confusion. I wanted you to check for flow at the same place as you connected the gauge.

Using your color ID scheme:

RED is the loader's power beyond outlet. That is where we need to check for flow. With the engine running there should be a constant flow of oill coming out of that point so you need to disconnect it and stick the end in the transmission filler so you don't pump the tractor dry while running the test.

That will completely disconnect the loader from the back hoe and 3pt. Then start the tractor and verify there is flow. If you got pressure at that connection there is almost surely going to be flow. Now run the loader through all functions. Everything should work and the only time that flow should ever stop is when you put the loader in FLOAT, or curl, or dump the bucket.

BTW - after all of this I am about 90% sure I know where the problem is, My educated guess is the power beyond conenction FROM the backhoe TO the tractor 3pt is blocked in some way. My analysis based on observed behaviors as I now understand them to be:

• The loader lift and power down won't work because it retruns exhaust oil to tank via the (presumably blocked) power beyond loop through the backhoe and 3pt.
• The loader lowers in FLOAT because pump and both cylinder ports are connected directly to tank via the return line on the loader valve.
• The bucket works because REGEN does not need a return and regular mode dump and curl both dump exhaust oil via the tank return port on the loader valve.
• The backhoe works because all of those BH70 spools dump exhaust oil straight to the tractor tank via the BLUE line
• The 3pt does not work because its supply of pressurized oil FROM the YELLOW backhoe power beyond outlet is (presumably) blocked.

Dan

Have weekend chores to do. Will retest LATER today and report back.

Can't thank u enough for you efforts. Way pass due diligence!

 

[TheOldHokie]

Have weekend chores to do. Will retest LATER today and report back.

Can't thank u enough for you efforts. Way pass due diligence!

I made my living debugging code - mine and a lot written by other people. I also did more than my share of remote diagnostic help so I am familiar with the human communication challenges. The diagnostic/communication process is the same for hydraulic systems and I enjoy the intellectual challenge of learning how the the different circuits operate and solving the puzzle when they get screwed up. My wife likes crossword puzzles - me not so much.....

I think the resolution of your problem is right around the corner....

Dan

 

[B2601WH]

I made my living debugging code - mine and a lot written by other people. I also did more than my share of remote diagnostic help so I am familiar with the human communication challenges. The diagnostic/communication process is the same for hydraulic systems and I enjoy the intellectual challenge of learning how the the different circuits operate and solving the puzzle when they get screwed up. My wife likes crossword puzzles - me not so much.....

I think the resolution of your problem is right around the corner....

Dan

Oh wise one as u predicted flow of hydraulic fluid and FEL operates as it should. Unable to field test due to inclimate weather.

Will check next week. By the way do u need a used pump with about 10,000 hours on it

Thanks again!

 

[TheOldHokie]

Oh wise one as u predicted flow of hydraulic fluid and FEL operates as it should. Unable to field test due to inclimate weather.

Will check next week. By the way do u need a used pump with about 10,000 hours on it

Thanks again!

Excellent!! Did you find and correct the blockage?

Dan

 

[B2601WH]

Excellent!! Did you find and correct the blockage?

Dan

Looked at this am. Hose clear, return pipe clear. What's left, u guessed it quick connect.

Replaced it with one I replaced from FEL early. All I can do is shake my head in disbelief.

Will test boom with a load later.

Should I be happy happy/content or should I continue to shake stick and use 4 letter words about the 1500lbs pressure?

 

[TheOldHokie]

Looked at this am. Hose clear, return pipe clear. What's left, u guessed it quick connect.

Replaced it with one I replaced from FEL early. All I can do is shake my head in disbelief.

Will test boom with a load later.

Should I be happy happy/content or should I continue to shake stick and use 4 letter words about the 1500lbs pressure?

I am not surprised it was the coupler and you should be very happy the problem has been found and corrected,

Your hydraulic pressure is still low and I would certainly attempt to correct that. Your pump(s) have been running at a constant 1500+ PSI for quite some time now. Contrary to popular belief that does not cause things to immediately grenade but its definitly not ideal for pump longevity Hopefully that low pressure is not caused by accelerated wear in the pump but you won't know that until you try adjusting the relief. I will say I am a little pessimistic. Those shims get you about 50 PSI meaning you would need 10!! If you add a shim to the releif and there is no increase in hydraulic pressure the pump is most likely bypassing internally. Then you can grapple (no pun intended) with the question of whether 1500 PSI is good enough or is an additional 500 pounds worth the cost of another pump.

Dan

 

[B2601WH]

I am not surprised it was the coupler and you should be very happy the problem has been found and corrected,

Your hydraulic pressure is still low and I would certainly attempt to correct that. Your pump(s) have been running at a constant 1500+ PSI for quite some time now. Contrary to popular belief that does not cause things to immediately grenade but its definitly not ideal for pump longevity Hopefully that low pressure is not caused by accelerated wear in the pump but you won't know that until you try adjusting the relief. I will say I am a little pessimistic. Those shims get you about 50 PSI meaning you would need 10!! If you add a shim to the releif and there is no increase in hydraulic pressure the pump is most likely bypassing internally. Then you can grapple (no pun intended) with the question of whether 1500 PSI is good enough or is an additional 500 pounds worth the cost of another pump.

Dan

I know this has been a journey and u have helped alot of (couldn't find orange)folks this week.

I've already replaced hydraulic pump(first post)and added .7mm/273 lbs of shim(#17 post). Still only have 1500lbs at FEL. I can keep adding, purchased more just in case.

I look at repairs( or u could call it reinvestment)as a cost of business, NOTHING lasts for ever.

 

[TheOldHokie]

I know this has been a journey and u have helped alot of (couldn't find orange)folks this week.

I've already replaced hydraulic pump(first post)and added .7mm/273 lbs of shim(#17 post). Still only have 1500lbs at FEL. I can keep adding, purchased more just in case.

I look at repairs( or u could call it reinvestment)as a cost of business, NOTHING lasts for ever.

If you want to test just the pump to see what it is capable of you need to build a pump test setup. If you own machines with hydraulic pumps this is a good rig to have in your tool chest:

1. Get a small hydraulic tee and a flow control valve
2. Put your pressure gauge in the middle leg of the tee
3. Hook the inlet on the flow control valve to one end of the tee and put a hose on the outlet. Run that hose into the hydraulic filler.
4. Hook the other end of the tee to the pump outlet
5. Fully open the flow control valve and then start the tractor
6. With the tractor running slowly begin to close the flow valve and watch the pressure rise.
7. Do not fully close the valve!! You should reach 2000 PSI long before the valve is fully closed. If you do not the pump is badly worn.

Here is a picture of mine.

Dan

 

[Vigo]

What's left, u guessed it quick connect.

you should be looking at item #20 in the diagram

Well at least i was right about something.

But i didn't get straight to it because i didn't understand this about the loader valve:

1. UP routes pressurized oil to the base end of teh cylinders and connects the rod end to the power beyond (open center) core in the valve. That exhaust oil goes then through the bucket spool and out the power beyond port
2. DOWN does the same thing in reverse
3. FLOAT connects pump and both lift cylinder work ports to TANK not power beyond and there is no pressure available to the bucket spool.
4. If the bucket spool is shifted to curl (not dump) at the same time as the lift spool is shifted to DOWN the oil goes to the rod end of the lift cylinder, the exhaust oil from those cylinders goes to the power beyond core where the bucket spool directs it to the rod end of the bucket cylinder, and finally bucket exhaust oil goes to TANK not power beyond

My older loader does not work that way (although it also has a totally undrilled PB boss) and my newer one has that little guide plate that makes it difficult to fully engage two functions, so i have never particularly noticed any difference between what it does in combination of two functions (i.e. bucket will not power either direction if loader is in float).

So my misunderstanding of when loader flow would be going out power beyond vs tank port sent me off the track, and if i can commit any of this to memory I'll have learned something here for future 'remote diagnostics'.

Glad you got it fixed!

 

[B2601WH]

Well at least i was right about something.

But i didn't get straight to it because i didn't understand this about the loader valve:


My older loader does not work that way (although it also has a totally undrilled PB boss) and my newer one has that little guide plate that makes it difficult to fully engage two functions, so i have never particularly noticed any difference between what it does in combination of two functions (i.e. bucket will not power either direction if loader is in float).

So my misunderstanding of when loader flow would be going out power beyond vs tank port sent me off the track, and if i can commit any of this to memory I'll have learned something here for future 'remote diagnostics'.

Glad you got it fixed!

Well at least i was right about something.

But i didn't get straight to it because i didn't understand this about the loader valve:


My older loader does not work that way (although it also has a totally undrilled PB boss) and my newer one has that little guide plate that makes it difficult to fully engage two functions, so i have never particularly noticed any difference between what it does in combination of two functions (i.e. bucket will not power either direction if loader is in float).

So my misunderstanding of when loader flow would be going out power beyond vs tank port sent me off the track, and if i can commit any of this to memory I'll have learned something here for future 'remote diagnostics'.

Glad you got it fixed!

Heck yah, more toys for the tool box, YES PLEASE!

Field test successfull. Handled 1200lbs of landscape blocks like a NEW tractor.

This winter I think I'll do a rebuild on the boom arms anyway. Call it preventive maintenance

Can't thank everyone who helped enough. I know I learned volumes. Hopefully this will help another novice owner.