Do I Have a Bad Valve?

BWBrown · Nov 13, 2009

On my Ford 1700, Bush Hog front end loader, I have a question:
The joystick functions correctly, move it left and right, the bucket curls.
Move the joystick full forward, it has a float detent, not so far forward the loader is in power down mode.
Pull the joystick partially back, the loader rises - so far so good...

Pull the joystick full back, the loader stays where it is, the valve sounds like the pressure relief is bypassing. Is there an adjustment, or is my valve bad?

I don't know the manufacturer of the valve. I bought the tractor new about '80, sold it in '87 then bought it back in '93. In the meantime, the other owner had installed the FEL (Bush Hog 1846 QT). It has functioned this way as long as I have had it, but the need to use the loader lift only in partly back position is something of a pain - the ability to simply pull full back on the stick to raise the loader would be great.

J_J · Nov 13, 2009

If your loader has QD's, try reseting them. Are there any check valves in the loader circuit.

AKKAMAAN · Nov 13, 2009

just an idea.....
Check so the maximum spool movement in the valve is not exceeded...should be around 3/8 to 1/2" or so........if you can pull that spool out to far when making lift operation, the land on the spool can block the port....with relief by pass as result.....see attached pic....

jinman · Nov 13, 2009

AKKAMAN, you did a great job of illustrating and describing what the problem must be. The lift spool must be exceeding it's maximum UP travel and blocking the ports. I was going to suggest that there might be a stop adjustment that limits joystick movement that has backed off. I would expect that to be internal to the valve. . .not sure.

AKKAMAAN · Nov 13, 2009

jinman said:
AKKAMAN, you did a great job of illustrating and describing what the problem must be. The lift spool must be exceeding it's maximum UP travel and blocking the ports. I was going to suggest that there might be a stop adjustment that limits joystick movement that has backed off. I would expect that to be internal to the valve. . .not sure.

well then we are two about it now...

Thanks for the support...

btw a forum is a learning /teaching board for hundreds of viewers/readers aswell as just a individual help desk...and I have a long history 25+ years, teaching fluid power on logging equipment....so it is natural to me to "take the next step"....wish more "expert" members would do the same, and this forum would become even better.....

J_J · Nov 13, 2009

You might try switching hoses on the valve and see if the trouble stays with the spool. When you pull back on the lever, do you have any pressure. It should not be going into relief unless something is blocking the flow, or the cylinders are fully extended or retracted.

BWBrown · Nov 14, 2009

It happens at any point in travel - the cyls are not fully extended. I have checked the QD connections, switched the hoses, my feeling all along is along the lines as diagrammed by akkamaan, and jinman has hit it spot on, on so many other posts - thanks to all of you for your suggestions!

I have played with quite a few cylinders, pumps and valves, but never INSIDE them. I'm fully aware that the ability to screw in a hose does not make me a valve repair guy.

I see no external stops on the lift function of the joystick, but it really does act like it is just coming back/out too far.
Could there be an internal detent, shoulder, stop pin or some other such thing broken? Could it be as easy as an adjustment.

If it is an easy fix, I'll have at it, OTOH, I'm not opposed to completely replacing the valve. I've lived with it longer than I care to think about.

AKKAMAAN · Nov 14, 2009

BWBrown said:
as diagrammed by akkamaan, and jinman has hit it spot on, on so many other posts - thanks to all of you for your suggestions!

I see no external stops on the lift function of the joystick, but it really does act like it is just coming back/out too far.

There is nothing else that make sense......

Could there be an internal detent, shoulder, stop pin or some other such thing broken? Could it be as easy as an adjustment.

If it is an easy fix, I'll have at it, OTOH, I'm not opposed to completely replacing the valve. I've lived with it longer than I care to think about.

jinman · Nov 14, 2009

I'm just going to sit back and watch and learn. While I have a good feeling of what is happening, AKKAMAAN has all the experience and knowledge. So I'll just happily sit on the sidelines and listen and learn.

Leejohn · Nov 14, 2009

Me too. Go for it brown it's a easy valve to repair.

BWBrown · Nov 14, 2009

Just got back to find these diagrams and instructions. You guys are amazing!
I'm hoping to get into it over the weekend.
I'll let y'all know what I find.
Bob

kennyd · Nov 15, 2009

BWBrown said:
If it is an easy fix, I'll have at it, OTOH, I'm not opposed to completely replacing the valve. I've lived with it longer than I care to think about.

If all the above great advice does not help find a fixable solution...I wanted to mention a good replacement for you from the Surplus Center:

9-7401

Good luck!

FLHayman · Nov 15, 2009

AKKAMAAN, any chance I could get you to write some service manuals for my JLG, John Deere, Kioti, and New Holland? I've never seen such a legible, detailed explanation of disassembly.........guess that means you don't write service manuals, right? Joking. Very well done, in all seriousness.

AKKAMAAN · Nov 15, 2009

FLHayman said:
AKKAMAAN, any chance I could get you to write some service manuals for my JLG, John Deere, Kioti, and New Holland? I've never seen such a legible, detailed explanation of disassembly.........guess that means you don't write service manuals, right? Joking. Very well done, in all seriousness.

Thank you FLHayman.....I do not write service manuals, but as a Forest Engineer, I do have a past teaching logging equipment, and the manuals has been the most important tool for that....

Purchasing heavy equipment for my former logging school, was not only a hardware issue, it was a sofware issue aswell.....If the equipment that we wanted did not have good software, we usually didn't buy it....

Software is crucial for good operation and maintenance.

You do not want to give instructions that can be misinterpreteded, instructions have to be safe that way......down time on equipment is way to expensive for that kind of hassle...

I know, that a forum like this, have a lot of expert advice coming and going.....but it is not worth any if it can't be understood.....not only the starter of a thread have interest in the answers, there is hundreds more, that also want to learn and know "how to fix"....

I think, to be part of a forum like this, it is more important to have skills in "how you post" than "what you post"....

I use Office Word, embedd a pic in a document, use textbox inserts and some fantasy......like this....video....40Mb+

http://akkamaan.com/hydraulic/pictures/example.avi

or
Edit:
http://www.youtube.com/watch?v=wD5NI7yBnbI

BWBrown made a few things right in his post....he explained well what was wrong, and he posted pictures of tractor and, most important, the valve.....

That helped and stimulated to make an effort for a useful reply post....

dcyrilc · Nov 18, 2009

jinman said:
I'm just going to sit back and watch and learn. While I have a good feeling of what is happening, AKKAMAAN has all the experience and knowledge. So I'll just happily sit on the sidelines and listen and learn.

AKKAMAAN,
How's your knowledge on tractor power steering? Could you pop over to my post on power steering rebuild in Repairs - I'ld like to pick your brain.

AKKAMAAN · Nov 19, 2009

dcyrilc said:
AKKAMAAN,
How's your knowledge on tractor power steering? Could you pop over to my post on power steering rebuild in Repairs - I'ld like to pick your brain.

I made a search for your power steering post y-day. wasn't sure if I found it....can you please post a link to it!

If it is that Orbitrol type steering valve, I have never repaired one, actually never had a problem with one either, but I know how they work internally....they are sorta little complex functionality and can be hard to figure out....

dcyrilc · Nov 19, 2009

AKKAMAAN said:
I made a search for your power steering post y-day. wasn't sure if I found it....can you please post a link to it!

If it is that Orbitrol type steering valve, I have never repaired one, actually never had a problem with one either, but I know how they work internally....they are sorta little complex functionality and can be hard to figure out....

Hopefully, this works for putting in a link.

http://www.tractorbynet.com/forums/parts-repairs/157149-2240-steering-rebuild.html

mmurphy · Feb 17, 2010

AKKAMAAN said:
well then we are two about it now...
Thanks for the support...

btw a forum is a learning /teaching board for hundreds of viewers/readers aswell as just a individual help desk...and I have a long history 25+ years, teaching fluid power on logging equipment....so it is natural to me to "take the next step"....wish more "expert" members would do the same, and this forum would become even better.....

I been wondering how you have been getting information out so fast!!! Keep up the good work, there is a couple of you guys that do just that. I am a type of guy that trys it and says "I will not do that again"!!

AKKAMAAN · Feb 17, 2010

mmurphy said:
I been wondering how you have been getting information out so fast!!! Keep up the good work, there is a couple of you guys that do just that. I am a type of guy that trys it and says "I will not do that again"!!