SOLVED: Loader raising slow all of a sudden

[severtki]

I was thrilled to find this old thread (https://www.orangetractortalks.com/...ed-loader-raising-slow-all-of-a-sudden.57937/) because I'm having the exact same issue as GunnerBob, with the exact same model (B3300SU w/loader LA504). I tried what worked for him without luck. Raising the bucket became suddenly extremely slow (would go up a bit, but it sounded like the hydraulic pump was straining to do so), but would accelerate for a brief burst when simultaneously using the curl/uncurl. All other hydraulic functions were working normally. I swapped out the hose lines as described above (white/yellow and red/blue) and had the same results as OP -- bucket lifted fine (opposite control orientation) but would not go down.

On the basis of that thread's solution, I replaced the two female quick couplers on the white and yellow lines, and now when reinstalled, there is ZERO up motion (not even the trickle of movement I had before). Other hydraulic functions still work. After noting this, I found that removing the white line was very difficult -- could not depressurize the line with the control stick to loosen it.

Any ideas on next diagnosis steps? I do note that the hydraulic oil filter is dented -- might that contribute to this? [And how much oil can I expect to spill out when I change that? just a small amount or the entire reservoir?]

I appreciate the excellent advice on this forum and would love to solve this without an expensive trailered trip to the shop...

Kirk

 

[Fastball714]

Make sure that your lever to raise and lower the 3 point hitch is in the center position. This has always been my solution, when fel would move very slow going up.

 

[TheOldHokie]

I was thrilled to find this old thread (https://www.orangetractortalks.com/...ed-loader-raising-slow-all-of-a-sudden.57937/) because I'm having the exact same issue as GunnerBob, with the exact same model (B3300SU w/loader LA504). I tried what worked for him without luck. Raising the bucket became suddenly extremely slow (would go up a bit, but it sounded like the hydraulic pump was straining to do so), but would accelerate for a brief burst when simultaneously using the curl/uncurl. All other hydraulic functions were working normally. I swapped out the hose lines as described above (white/yellow and red/blue) and had the same results as OP -- bucket lifted fine (opposite control orientation) but would not go down.

On the basis of that thread's solution, I replaced the two female quick couplers on the white and yellow lines, and now when reinstalled, there is ZERO up motion (not even the trickle of movement I had before). Other hydraulic functions still work. After noting this, I found that removing the white line was very difficult -- could not depressurize the line with the control stick to loosen it.

Any ideas on next diagnosis steps? I do note that the hydraulic oil filter is dented -- might that contribute to this? [And how much oil can I expect to spill out when I change that? just a small amount or the entire reservoir?]

I appreciate the excellent advice on this forum and would love to solve this without an expensive trailered trip to the shop...

Kirk

Do ypu have any other hydraulic options on the tractor:

Third function?
Rear remotes?
Backhoe?

No trip to dealer needed - just some well focused diagnostic testing.

Dan

 

[severtki]

Do ypu have any other hydraulic options on the tractor:

Third function?
Rear remotes?
Backhoe?

No trip to dealer needed - just some well focused diagnostic testing.

Dan

No special equipment, just the standard loader/joystick and 3pt.
Am I right in guessing it's likely a block in the yellow work port? If not at the quick coupler, where else might I locate the block to clear it?

 

[TheOldHokie]

No special equipment, just the standard loader/joystick and 3pt.
Am I right in guessing it's likely a block in the yellow work port? If not at the quick coupler, where else might I locate the block to clear it?

Since you replaced those couplers i would be inclined to rule thàt out.

Lets get some specifics on your problem. Some of this may seem repetitive but I eant to be sure we are in sync about what happened and how.

Was everything working OK then the loader simply stopped?

Does bucket curl and dump work correctly?

Does 3pt lift go up and down correctly and stop at intermediate heights in response to position control lever?

Does lowering 3pt lift change loader behavior?

Dan

 

[severtki]

Since you replaced those couplers i would be inclined to rule thàt out.

Lets get some specifics on your problem. Some of this may seem repetitive but I eant to be sure we are in sync about what happened and how.

Was everything working OK then the loader simply stopped?

Does bucket curl and dump work correctly?

Does 3pt lift go up and down correctly and stop at intermediate heights in response to position control lever?

Does lowering 3pt lift change loader behavior?

Dan

Great questions!

Not certain, but I think the raise bucket motion was getting gradually slower over a few weeks (infrequently used). One day I really noticed it was super sluggish, which led me to investigate. Everything else has been normal -- curl and dump is all fine. 3pt goes up and down correctly in response to position control including stopping midway.

After sitting overnight, when I fired it up this morning I was able to get a short burst of up motion in the bucket and it raised a couple inches. Nothing further.

Thanks for helping diagnose, Dan!

 

[TheOldHokie]

Great questions!

Not certain, but I think the raise bucket motion was getting gradually slower over a few weeks (infrequently used). One day I really noticed it was super sluggish, which led me to investigate. Everything else has been normal -- curl and dump is all fine. 3pt goes up and down correctly in response to position control including stopping midway.

After sitting overnight, when I fired it up this morning I was able to get a short burst of up motion in the bucket and it raised a couple inches. Nothing further.

Thanks for helping diagnose, Dan!

Sorry - should have asked in last post - does loader lower in float?

Dab

 

[severtki]

Sorry - should have asked in last post - does loader lower in float?

Dab

It does!

 

[TheOldHokie]

It does!

Hmmmmm.

That tells is the "UP" coupler on the loader valve is working in the "DOWN" direction.

So now lets check it in the "UP" direction. If you have any questions about the folloeing please ask before running the test.

With tractor off and loader on the ground disconnect the rod end female coupler from the valve and remove it from the end of the hose. Put the end of the hose in a clean can or bucket thst will hold a gallon or more. Now start the tractor and with engine at roughly 1000 RPM try to raise the loader.

If the loader comes up we know the base end coupler is working in both directions snd the problem os somewhere on the return side


If the loader does not come up we have found the location of the problem - the base end coupler is not flowing In the "UP" direction.

Reconnect the hose and coupler. Awaiting the results before deciding where we go next.

Dan

 

[severtki]

Hmmmmm.

That tells is the "UP" coupler on the loader valve is working in the "DOWN" direction.

So now lets check it in the "UP" direction. If you have any questions about the folloeing please ask before running the test.

With tractor off and loader on the ground disconnect the rod end female coupler from the valve and remove it from the end of the hose. Put the end of the hose in a clean can or bucket thst will hold a gallon or more. Now start the tractor and with engine at roughly 1000 RPM try to raise the loader.

If the loader comes up we know the base end coupler is working in both directions snd the problem os somewhere on the return side


If the loader does not come up we have found the location of the problem - the base end coupler is not flowing In the "UP" direction.

Reconnect the hose and coupler. Awaiting the results before deciding where we go next.

Dan

OK -- just checking before I do this: I traced the hose that connects to the "rod end" of the bucket raise cylinder to the white line. So for this test, I'll disconnect the quick-connect for the white hose, remove the female coupler from the hose (one of the two that I just replaced), and run the test?

I understand that this white hose is the return line when raising the bucket? This is also the one that is very hard to relieve pressure on and doesn't want to come off the quick-connect, so I suspect you're onto something with this line of thinking! I'll try this a little later today, if I did understand the process correctly.
Thanks!!
Kirk

 

[TheOldHokie]

OK -- just checking before I do this: I traced the hose that connects to the "rod end" of the bucket raise cylinder to the white line. So for this test, I'll disconnect the quick-connect for the white hose, remove the female coupler from the hose (one of the two that I just replaced), and run the test?

I understand that this white hose is the return line when raising the bucket? This is also the one that is very hard to relieve pressure on and doesn't want to come off the quick-connect, so I suspect you're onto something with this line of thinking! I'll try this a little later today, if I did understand the process correctly.
Thanks!!
Kirk

Thats exactly right. The rod end (white) coupler is the route return oil travels when the loader is raised. If thst route is blocked the cylinder is hydraulically locked and cannot be extended.

I should also mentiom that the 3pt should also be in the down position while running all tests.

In tje interest of speeding things up lets also add one more thing to this test. If the loader comes up try to lower it before reconnecting the coupler and without going into float.

Dan

 

[Henro]

Dan, I believe the OP's tractor does not have position control, so the 3PH lever normally is in the center position, and moved off center to lower or raise the 3PH.

Are you saying that the 3PH lever should be held off center, in the down position, when running the test? I would not have expected that...

 

[TheOldHokie]

Dan, I believe the OP's tractor does not have position control, so the 3PH lever normally is in the center position, and moved off center to lower or raise the 3PH.

Are you saying that the 3PH lever should be held off center, in the down position, when running the test? I would not have expected that...

I was not aware the tractor did not have position control. Whatever it has the 3pt control valve needs to be in neutral.

Dan

 

[TheOldHokie]

Dan, I believe the OP's tractor does not have position control, so the 3PH lever normally is in the center position, and moved off center to lower or raise the 3PH.

Are you saying that the 3PH lever should be held off center, in the down position, when running the test? I would not have expected that...

So the tractor has a feedback linkage. Could not find a manusl. What function does the feed back provide? This may be important if the problem does not turn out to be a bad coupler.

 

[Henro]

So the tractor has a feedback linkage. Could not find a manusl. What function does the feed back provide? This may be important if the problem does not turn out to be a bad coupler.

I am not sure I know the answer. BUT I think, that tractor uses what Kubota calls a quarter inching valve. That means if you move the handle quickly, and return it to center, the 3PH moves a bit, maybe a quarter inch, don't know. That is the way the 3PH works on my BX, and I THINK it is the way it works on the OP's tractor.

 

[TheOldHokie]

I am not sure I know the answer. BUT I think, that tractor uses what Kubota calls a quarter inching valve. That means if you move the handle quickly, and return it to center, the 3PH moves a bit, maybe a quarter inch, don't know. That is the way the 3PH works on my BX, and I THINK it is the way it works on the OP's tractor.

I located an Owners Manual that explains how to use it but not how it works. If the OPs problem turns out to be downstream I will register for a class on the theory amd operstion of the qusrter inching valve system.

Thanks for the heads up !!!

Dan

 

[severtki]

I located an Owners Manual that explains how to use it but not how it works. If the OPs problem turns out to be downstream I will register for a class on the theory amd operstion of the qusrter inching valve system.

Thanks for the heads up !!!

Dan

Correct on the quarter inching valve. I'll keep it in neutral position for the test -- I understand it now and will get that done in a couple hours.

Question re: float -- does that function just open a circuit through the valve between the rod end (white) and cylinder end (yellow) hoses to allow fluid to freely flow? If nothing else, I'm beginning to get an understanding of how the system all works...

 

[eserv]

If the curl and dump are working good the problem will have to be in the lift circuit. Likely one of the couplers have failed. when they are working properly the ball or pintle on the male and female coupler are designed to force each other to open. Sometimes the mechanism inside them will fail and only one of the balls or pintles will be forced open. When this happens the couplers actually operate like a check valve and will only allow oil to flow in one direction. If you push in on the ball or pintle it should only go flush with the surface of the coupling, if it goes further it will not hold the pintle open on the companion fitting. It is most often the male ends that fail, The retainer inside the coupler that the spring forces against will have broken or otherwise moved out of position allowing the pintle or ball to retract too far into the coupling.

 

[severtki]

If the curl and dump are working good the problem will have to be in the lift circuit. Likely one of the couplers have failed. when they are working properly the ball or pintle on the male and female coupler are designed to force each other to open. Sometimes the mechanism inside them will fail and only one of the balls or pintles will be forced open. When this happens the couplers actually operate like a check valve and will only allow oil to flow in one direction. If you push in on the ball or pintle it should only go flush with the surface of the coupling, if it goes further it will not hold the pintle open on the companion fitting. It is most often the male ends that fail, The retainer inside the coupler that the spring forces against will have broken or otherwise moved out of position allowing the pintle or ball to retract too far into the coupling.

Thanks for this explanation of the ball/pintle. Having just replaced the female quick coupler end on both of the hoses on that loop, does that suggest the male end might be the issue?
It appears the flow from cylinder back (female coupler side) to valve (male coupler) on the white loop might be blocked. Would that be consistence with the male coupler failing?

 

[TheOldHokie]

Correct on the quarter inching valve. I'll keep it in neutral position for the test -- I understand it now and will get that done in a couple hours.

Question re: float -- does that function just open a circuit through the valve between the rod end (white) and cylinder end (yellow) hoses to allow fluid to freely flow? If nothing else, I'm beginning to get an understanding of how the system all works...

I can see the grey cells are working full time

FLOAT connects rod and base ends to tank allowing free oil flow to tank in both directions. Pressureized oil from the pump contines uninterrupted to power beyond - e.g the 3pt valve.

Contrast that to DOWN where tank is not used. Instead pressurized oil is diverted to rod end and pressurized return oil is sent to power beyond - e.g the 3pt valve.

Mull on that a bit and you may see a method in my madness.

Dan

PS - I suspect a coupler and the goal is to identify which one(s).