L2850/BF500 Pressure test question

[Sobrbiker]

I’m looking to test relief valve and pressure on my L2850 with attached BF500 FEL.
I’ve searched the old threads I could find, but have questions:
-could I insert a 3000psi test gauge into the quick disconnect between the front hydraulic block and the loader control valve body by using quick disconnects attached to a tee?
This seems logical to me, that at max rpm static it would be reading pressure available to everything, or am I missing something?

-If that’s plausible, are the factory QD fitting compatible with ISO 7241-A 3/8?

I’ve got the manual, and am aware relief valve should be 2204-2295psi. Would this be the pressure available to loader when 3Ph implement is grounded and loader is grounded?

—Also, on a 1987 tractor with unknown history (hour meter was dead at 1517 when I bought its couple years ago), rather than just trying to adjust relief valve with shims (if deficient) should I get new spring and valve parts (if the setup I’m looking to do indeed tests the pressure properly)?

Thanks for all the knowledge y’all provide. I’m a heavy equipment operator (and moderately mechanically inclined), but am still wrapping my head around the tractor ins and outs.

 

[TheOldHokie]

I’m looking to test relief valve and pressure on my L2850 with attached BF500 FEL.
I’ve searched the old threads I could find, but have questions:
-could I insert a 3000psi test gauge into the quick disconnect between the front hydraulic block and the loader control valve body by using quick disconnects attached to a tee?
This seems logical to me, that at max rpm static it would be reading pressure available to everything, or am I missing something?

-If that’s plausible, are the factory QD fitting compatible with ISO 7241-A 3/8? View attachment 156817 View attachment 156818

I’ve got the manual, and am aware relief valve should be 2204-2295psi. Would this be the pressure available to loader when 3Ph implement is grounded and loader is grounded?

—Also, on a 1987 tractor with unknown history (hour meter was dead at 1517 when I bought its couple years ago), rather than just trying to adjust relief valve with shims (if deficient) should I get new spring and valve parts (if the setup I’m looking to do indeed tests the pressure properly)?

Thanks for all the knowledge y’all provide. I’m a heavy equipment operator (and moderately mechanically inclined), but am still wrapping my head around the tractor ins and outs.

Sounds like you dont have an actual problem but would like to have one.

To test tractor pressure you do not use a tee. You plug the gauge straight into the coupler. Factory couplers were 3/8" Faster HNV, ISO 7241-B

If pressure is low you dont know if its the relief valve, pump, or both. As far a a replacing parts - if it aint broke dont fix it.

Dan

 

[Russell King]

Your idea is close and would show pressure when the valve actuates a cylinder but not when valve is not in use.

I think you should put your gauge into one of the lift hose connected to the valve.

See post #3 in this thread for information

Hydraulic performance fade.

My Kubota SVL 75-2 operates fine until it is good and warmed up, then the boom and bucket will barley move. Fluid is clear, level is good, and the filter was just change. 3100 hours on the machine. I have talked with several Kubota shops and they all tell me they have never heard of such a...

www.orangetractortalks.com

 

[Russell King]

@TheOldHokie - you did NOT write a reply - or the systems did not record it!

 

[Sobrbiker]

Sounds like you dont have an actual problem but would like to have one.

To test tractor pressure you do not use a tee. You plug the gauge straight into the coupler. Factory couplers were 3/8" Faster HNV, ISO 7241-B

If pressure is low you dont know if its the relief valve, pump, or both. As far a a replacing parts - if it aint broke dont fix it.

Dan

I don’t know what you mean by “would like to have” a problem. I’d like to test my relief valve to know where it’s letting off at.
I didn’t bring up that I’m trying to get the position control on my 3PH properly set, as no matter how I adjust the feedback rod, when it hits the top the the supply line to FEL valve box is stiff and loader jerks when operated-unless I move position control lever away from the the stop (allowing flow through the position control valve) and this leads me to question the proper operation of the relief valve.

Back to the quick connect to the FEL valve (thanks for the clarity on the size) I had inferred from other posts on relief valves that I’ve read that if I just dead headed that with a pressure gauge it could damage the pump.

I was just hoping I could check the relief valve tying into the FEL quick connects, seemed the quickest and easiest place if it’ll work.

 

[TheOldHokie]

[

I don’t know what you mean by “would like to have” a problem. I’d like to test my relief valve to know where it’s letting off at.
I didn’t bring up that I’m trying to get the position control on my 3PH properly set, as no matter how I adjust the feedback rod, when it hits the top the the supply line to FEL valve box is stiff and loader jerks when operated-unless I move position control lever away from the the stop (allowing flow through the position control valve) and this leads me to question the proper operation of the relief valve.

Back to the quick connect to the FEL valve (thanks for the clarity on the size) I had inferred from other posts on relief valves that I’ve read that if I just dead headed that with a pressure gauge it could damage the pump.

I was just hoping I could check the relief valve tying into the FEL quick connects, seemed the quickest and easiest place if it’ll work.

The relief valbe is in the outlet block and to determine the operating pressure you deadhead the pump. Straight from the Kubota workshop manual. Just connect the gauge to that hose - simple as it gets.

The relief valve has nothing to do with the feedback adjustment. When the feedback linkage does not properly return the position control to neutral you deadhead the pump against that very same relief which protects the pump from damage.

Your problem is the feedback adjustment not the relief valve.

Dan

 

[Russell King]

@TheOldHokie
Could there be some problem in the three point control system valve? I recall some thread that showed an extremely jerky three point system that ended up being something in the “teeter totter” control system. (I can’t recall a word to search to find that thread)

I doubt that is the problem but is it a possibility?

@Sobrbiker
Here is a thread that shows how to adjust the feedback rod on an older Kubota, in post #4. I assume you can find similar instructions for your tractor or possibly use these to adjust your tractor.

L305DT lift arms not working right

Let me give you a little history on this tractor in case there is some thing here that I missed that could be related to the current problem. 3yrs. ago they parked the tractor because they thought they were getting diesel in the motor oil, it had gotten water in the trans housing and froze...

www.orangetractortalks.com

 

[TheOldHokie]

@TheOldHokie
Could there be some problem in the three point control system valve? I recall some thread that showed an extremely jerky three point system that ended up being something in the “teeter totter” control system. (I can’t recall a word to search to find that thread)

I doubt that is the problem but is it a possibility?

@Sobrbiker
Here is a thread that shows how to adjust the feedback rod on an older Kubota, in post #4. I assume you can find similar instructions for your tractor or possibly use these to adjust your tractor.

L305DT lift arms not working right

Let me give you a little history on this tractor in case there is some thing here that I missed that could be related to the current problem. 3yrs. ago they parked the tractor because they thought they were getting diesel in the motor oil, it had gotten water in the trans housing and froze...

www.orangetractortalks.com

His loader problem is caused by the position control valve not returning to neutral when the control handle is moved to the full up position. The feedback linkage is supposed to do that automatically and its not. He describes doing it manually.

The "teeter-totter" (if used on that tractor) is part of the internal feedback linkage and could be the culprit but more likely its the external adjustment. The OP needs to focus on understanding what that external rod does and how its adjusted.

Dan

 

[Sobrbiker]

Dan-
copy that.

I’ve got my head pretty well wrapped around how the position control “teeter totter” works, but am trying everything I can to not have to tear everything off that has to come off to get to that little bugger.
I’m thinking I may be having issues because I’m trying to set feedback adjustment with a heavy implement (MF-18 Massey scraper box) attached.
I tried the local Kubota shop to get info from their tech on setting position control and draft control back to baseline settings, but they were less than helpful.

 

[TheOldHokie]

Dan-
copy that.

I’ve got my head pretty well wrapped around how the position control “teeter totter” works, but am trying everything I can to not have to tear everything off that has to come off to get to that little bugger.
I’m thinking I may be having issues because I’m trying to set feedback adjustment with a heavy implement (MF-18 Massey scraper box) attached.
I tried the local Kubota shop to get info from their tech on setting position control and draft control back to baseline settings, but they were less than helpful.

I dont have the WSM but to set position control feedback you do not need an implement:

1. Disable draft control
2. Raise position control lever to top of travel
3. Adjust length of feedback rod to point where relieve valve closes. That should be an audible event.

Adjusting draft is a different process and typically requires a "special tool".

The WSM is quite clear on how to do both. I suggest you get a copy.

Dan

 

[Sobrbiker]

I dont have the WSM but to set position control feedback you do not need an implement:
———————————————————

The WSM is quite clear on how to do both. I suggest you get a copy.

Dan

Good morning Dan.
I appreciate the input, but “get a manual” not what I’m looking for. The “I don’t have a manual/the manual is clear” statement is a little confusing…

It takes only a little research (even just here on OTT) to realize Kubota has a myriad of different position control setups, with particular peculiar to each model line.
I’m looking for help because I’m in possession of a tractor that has 35+ yrs of unknown history of prior owners monkeying with it and am trying to get it back to a baseline to know its starting from where it should, and the WSM I have, nor my local dealer) don’t clearly explain what I’m looking for.
My direct question in the last post you responded to was not “do I need an implement attached”, rather it was looking to know if having an implement attached is interfering with finding the proper base setting to see if I do indeed have a functional problem that needs further work up deeper in the system (ie-I can’t tell if it’s a problem with someone prior jacking with the teeter totter if I don’t get the feedback loop as it should be to begin with, and maybe trying to get the feedback rod set to factory with a 900# 72” Gannon box attached is not the way to get there).

This all started just because I was asking if I was on the right or wrong track of how to check the front hydraulic block’s relief valve by tapping into the FEL feed circuit because I don’t have the flow meter or specialty tools called for in the WSM, and I’m trying to find if the method that made sense in my head would do any damage.

I’ll probably drop the box and reset feedback loop adjustment (most likely safer anyway without it on). Additionally that way I should be able to hear/sense relief opening while adjusting because I can’t adjust with tractor running with box going up and down (I could, but I like my hands and arms the way they are now).

I’m sure you’ve forgotten more about these systems than I know, but we’ve all gotta start somewhere.

 

[TheOldHokie]

Good morning Dan.
I appreciate the input, but “get a manual” not what I’m looking for. The “I don’t have a manual/the manual is clear” statement is a little confusing…

It takes only a little research (even just here on OTT) to realize Kubota has a myriad of different position control setups, with particular peculiar to each model line.
I’m looking for help because I’m in possession of a tractor that has 35+ yrs of unknown history of prior owners monkeying with it and am trying to get it back to a baseline to know its starting from where it should, and the WSM I have, nor my local dealer) don’t clearly explain what I’m looking for.
My direct question in the last post you responded to was not “do I need an implement attached”, rather it was looking to know if having an implement attached is interfering with finding the proper base setting to see if I do indeed have a functional problem that needs further work up deeper in the system (ie-I can’t tell if it’s a problem with someone prior jacking with the teeter totter if I don’t get the feedback loop as it should be to begin with, and maybe trying to get the feedback rod set to factory with a 900# 72” Gannon box attached is not the way to get there).

This all started just because I was asking if I was on the right or wrong track of how to check the front hydraulic block’s relief valve by tapping into the FEL feed circuit because I don’t have the flow meter or specialty tools called for in the WSM, and I’m trying to find if the method that made sense in my head would do any damage.

I’ll probably drop the box and reset feedback loop adjustment (most likely safer anyway without it on). Additionally that way I should be able to hear/sense relief opening while adjusting because I can’t adjust with tractor running with box going up and down (I could, but I like my hands and arms the way they are now).

I’m sure you’ve forgotten more about these systems than I know, but we’ve all gotta start somewhere.

View attachment 156895

Disable draft control if so equipped, raise the position control lever to top of travel and adjust the length of the feedback rod to bring lift arms as high as possible while preventing relief vslve from opening. As simple as it gets and applicable to every model Kubota I have ever looked at.

Dan

 

[Sobrbiker]

Thanks-
So just ignore 4, 5, 6 and don’t bother with 7 (and how do I know if float is achieved at bottom of stories anyway)?

 

[Sobrbiker]

You may be able to see why I’m interested in knowing where relief valve actuates is….

 

[TheOldHokie]

You may be able to see why I’m interested in knowing where relief valve actuates is….

You seem to want to argue rather than execute a simple adjustment. Relief valve pressure has ZERO to do with that adjustment.

From the WSM:

#4 sets top of travel on the positiin control lever.
#5:is finding the spot where the relief operates signaling the pump is deadheaded.
#6 is lowering lift to point below #5 where relief is closed and pump is unloading to tank

Exactly what I described using different words. You will have float at the bottom but if you dont increase the number of turns in #6

Your loader problem will be resolved when the position control linkage kicks the valve into neutral before the lift arms hit the physical end of travel deadheading the pump. Simple as that.

Dan

 

[Sobrbiker]

Not looking to argue, and thanks for filling in the gaps. My apologies for it not being a simple adjustment to me…but it will be simpler next time if there is one.

For this model at least, the control arm stopper spec for setting where the relief valve actuates (#4) is well away from the top of travel for some reason.

Regardless of how you perceived my intent with the questions, I’m happy to report that disconnecting the implement made the difference in being able to get the feedback adjustment properly set, something I couldn’t get done before.
Full range of motion on 3PH with out inducing “jerkiness” to the FEL circuit.

I’m still planning to check relief setting once I get a gauge setup.

 

[Sobrbiker]

@Sobrbiker
Here is a thread that shows how to adjust the feedback rod on an older Kubota, in post #4. I assume you can find similar instructions for your tractor or possibly use these to adjust your tractor.

L305DT lift arms not working right

Let me give you a little history on this tractor in case there is some thing here that I missed that could be related to the current problem. 3yrs. ago they parked the tractor because they thought they were getting diesel in the motor oil, it had gotten water in the trans housing and froze...

www.orangetractortalks.com

Thanks Russell, I did peek at that thread and appreciate the response. The L2850 position control adjustment is a little different (or mine was way out of whack) as I wound up shortening the rod to get it back in balance.

The amount of unknown things done to my first tractor by 35 years of other owners is really making my learning curve interesting.