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.