Loader control valve not curling bucket

[gs12jdg]

Hello,
I have a Mahindra 2810 tractor and I think there is a problem with the control valve / joystick for the loader. I don't know much about hydraulics, and I bought the tractor used so I am not sure if the control valve is the factory valve or if it has been replaced somewhere along the line.
I used the loader for several hours this weekend and then at the end of the day all of a sudden the bucket would not curl. It will still go up, down, and dump but just will not curl.
I reconnected all of the quick connectors to make sure they have a tight fit. They all seem to be in good working condition. I also swapped the dump and curl lines, and doing so I could curl the bucket but not dump it, so that tells me the lines themselves are in good shape.
The problem is when I try to pull the joystick left to curl the bucket, it doesn't really want to go left and nothing happens. I took the rubber boot off the joystick and from what I see the front left cylinder is supposed to go down in order for the bucket to curl. I tried pushing it down by hand and pulling hard to the left on the joystick, but IT will not go down. What could be the possible reason(s) why this cylinder will not go down?

I appreciate your help.

 

[/pine]

Since you've checked the QDs/hoses etc... the next thing I would do is remove the bottom of the spool caps and see what you find...make sure that the bolts that hold the springs in place are tight...remove any accumulated rust,gunk etc..apply new grease before closing...

BTW, you can safely remove the caps without fear of getting into something you are not already familiar with...if anything (ball bearings etc.) fall out they need to be replaced anyway...a cheap and easy way to fix many loader valve issues...

Good Luck...

 

[gs12jdg]

Thank you for the reply. Pardon my ignorance but what is a spool cap? Below is a picture I took when I removed the joystick boot today. The cylinder I circled in red is what I think is the problem. When I try to pull the joystick which should make that cylinder go down and in turn curl the bucket, nothing happens. The joystick will not really go to far left of center. Also, I noticed a small thing shaped like the outer half of a ball bearing (circled in green in the picture). What could this be, and where does it go?

 

[/pine]

You had not mentioned the joystick or I missed it...just make sure all the ball/socket and any articulated joints do not seem overly worn or faulty...

The "bottom caps" will be on the bottom of the valve...in most cases there are two (Allen head) bolts that secure each cap...

if you find everything copacetic under the bottom caps...I would try manually moving the spools (sans joystick) to make sure the valve is OK...

 

[gs12jdg]

When you say "spools" are you referring to the 2 cylinders under the rubber boot that move up and down depending on which way I move the joystick? If so, the one on the right moves fine (this one appears to lower and dump the bucket depending on whether it is up or down). The one on the left will go up, but it will not go down when I pull the joystick left. I tried pushing it down by hand as well but it would not go down.

Just so I am clear, in the picture below, are you saying to remove the hex bolt (circled in red) and the one on the other side that is not visible in the picture. What I am looking for when I remove these bolts?

 

[/pine]

No, the caps I'm talking about are on the very bottom of the valve assembly...they should look like little round canisters...( it is a general maintenance procedure to remove and inspect under the bottom caps periodically...they tend to accumulate moisture that leads to rust etc...)

a "spool" is the machined rod that moves up and or down in the valve body...

I suspect your issue lies in either something you'll find under the bottom caps or with the joystick mechanisms...

 

[GPintheMitten]

I'm on my phone now so harder to copy a picture. But if you look at the picture of the valve in this link, I think slashpine is talking about the 2 cylinder looking things on the left side of the picture opposite from the control levers.
Prince Two-Spool Control Valve, Model# RD522GCGA5A4B1 | Control Valves| Northern Tool + Equipment

 

[GPintheMitten]

Try this.

 

[J_J]

Remove the gimbles on the spools and tell me if both spools move in and out the same.

You could have a piece of crud, rust,rubber, metal blocking the movement of the spool.

You could remove the cans and parts of the curl spool and remove it and inspect for damage or debris.

Awhile back one guy had a piece of the load check valve came apart and blocked the spool.

 

[gs12jdg]

Thanks everyone for the replies. It's great to know there are people out there that are smarter than me that our willing to help. I am very new to hydraulics so words like spool and gimble and a few others used are still foreign to me but I think I follow. That picture is helpful. I will go back out tomorrow and look for 2 cylinder shaped cap things on the bottom of the valve with hex bolts holding them on. I will remove the caps and clean out any gunk that may be in there and report the results.
Question: do I have to worry about any springs or bearings or anything falling out when I remove the caps.

 

[J_J]

Yes, you do have to be careful as there are balls and springs under the cap.

Put a rag or/and a magnet under the parts .

You might need a manual to reassemble.

 

[Egon]

A couple of weeks ago I had the same proble with no curl but it was a very obvious broken line.

Suggest you disconnect the quick couples and with the tractor off work the joy stick looking for slop or maybe a missing pin etc. or something jammed in that prevents movement.

 

[wdchyd]

I would NOT advise taking any valves apart till you rule it out first....otherwise you will have a can-o-worms and two problems

swap the hoses from the lift circuit with the curl circuit and see if the problem changes......and look closely at the spools and make sure they are stroking in and out properly

If after the hose swap if the problem changes to the lift circuit then you have a cyl problem (very common BTW)....blown piston seal or nut coming off the end of the rod inside one of the curl cylinders

(All this assumes you have checked all your QD's for proper connection first)

 

[gs12jdg]

I already swapped the hoses and confirmed that I can get the bucket to curl this way.
When you say spool, I am still not sure what you are referring to. Below is a picture that I took of the control valve where the joystick is connected to it. IS the vertical cylinder thing that I circled in red the spool? If so, this is the thing that is not moving down when I pull the joystick to the left. I cannot push it down by hand either. Its like something is jamming it, but I do not see anything in the picture that would be causing the jam. I think it may be something underneath this cylinder that is preventing it from going down, but I am not sure how to inspect underneath it.
Also, if you look at the picture I also circled a little half ball shaped piece of metal that was just sitting inside the boot. Where could this piece have come from?

I also noticed that the joystick does not return to center and flops around a lot. Could there be a broken spring somewhere? This is the first time I ever looked at a control valve so I am not sure where the spring would even be.

 

[J_J]

If the spool will not center, then you have to remove the can on the bottom of the curl spool and remove the parts on the end of the spool.

It will have a spring and two spring cups.. If may have some balls and spring for the regen if your spool has regen.

You should have a manual before taking things apart.

Who makes the valve, and model number?

 

[Egon]

Is the other half of that ball around somewhere in the control stick action?

The control stick is also bent in the thread area. Is this normal or planned.

 

[wdchyd]

I am not sure where the spring would even be.

Yes, the red circled part is the spool.....the spring/can/bonnet/balls will be directly inline on the back side of the valve body (underneath)

 

[gs12jdg]

I went back down to the farm today and took a video (see link below). As you can see when I pull the lever to the right in the video the spool on the right side of the video should lower, but it does not. Is this clearly a problem with the joystick area, or could there be something under the spool that is not allowing it to lower?
I am a little confused as to what possible things could cause the spool not to go down. Even if there was no hydraulic fluid in the system, shouldn't this spool go up and down with relative ease? I am apprehensive about removing the spool caps and having to reassemble springs and bearings.
I did notice that there is a little pin that is missing from underneath one of the circular ball joint things, but I just stuck a nail through the hole for the time being for support and that did not affect any change.

https://www.youtube.com/watch?v=uhvBctFyjxo

The control serial plate shows it is a Nimco 10373-2s.

Thank you everyone for your replies.

 

[J_J]

Does your loader valve look like any of these.

Special Loader Valves

10373-2S.
It is CV112 power beyond unit.

http://www.nimco.co/Webs/_Base/Default/uploadedFiles/documents/Nimco/CV112.pdf

Maybe this will help.

http://www.tractorbynet.com/forums/...64099-nimco-fel-joystick-valve-diagram-2.html

 

[gs12jdg]

Is the other half of that ball around somewhere in the control stick action?

The control stick is also bent in the thread area. Is this normal or planned.

No, that one piece was the only spare piece lying inside the boot when I opened it. Its not really a half ball, its more like a metal contact lens. I have no clue where it could have come from. The only thing I can think of is that maybe the previous owner rigged up one of the ball sockets to tighten things up or something.