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Discussion Starter #1
Last night while plowing snow the curl/dump function on my JD 410 loader stopped working when I was banging the bucket against the dump stop to clear snow from the bucket. It seems to be trying to work when I activate either the curl or dump function the engine rpm decreases slightly like the fluid is being restricted some how. I checked that the function of the QD when disconnected, to insure the flow of fluid when the button on the end of the QD is depressed. The bucket can be moved thru its range of motion by hand with no resistance. I have switched the hoses with no change in operation of the bucket. This only effects the bucket as I can still raise and lower the lift arms.
 

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First off...welcome to MTF....sorry to hear that you are having that problem...especially in the middle of a job...you say you changed the hoses...did you disconnect the boom hoses and connect them to where the bucket hoses had been....and put the bucket hoses where the boom had been connected....or did you just interchange the 2 hoses for the bucket?...I am going to move this over to the hydraulics forum, where you might get more response
 

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If you switched the bucket and boom hoses at the ports, my (quick) guess is that a cylinder failed. I believe the two cylinders are connected in parallel, so one cylinder failure is enough to disable it.

Perhaps a piston snapped off the end of the shaft? Disconnecting the shaft and moving the shafts manually should give you a good indication of which one failed.

Having said the above, I am not an expert on this topic; but it gives you something relatively easy to check. Hopefully others more knowledgable than I will chime in.

Luis
 

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Not sure if I follow the question.

I am assuming that your loader hydraulics connect to the tractor hydraulics at the 4 ports. I would swap the connections in pairs to verify it is the loader and not the tractor.

(Still a newbie, too)
Luis
 

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Before answering that can you verify what you have already done?...it will help avoid getting confused as we progress.....I think it is something within the spool valve....so explain what hoses you switched around...and have you left them like that?...or switched back?...My very first thought was either a clogged filter or maybe not enough fluid....but I think you would get a lot of resistance when trying to move the bucket by hand if either one were the case...and it should effect the boom also
If inside the spool valve ( controls) you should be able to either bring it to a hydraulics shop and have it rebuilt or get a rebuilding kit...I think kits are available from Surplus Warehouse....if you pop it open yourself and find a blown O ring you may find them at a good hardware store...or graingers or McMaster Carr...make sure it is compatible with the fluid you are using
 

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Does your curl circuit have a regen / detent feature? I’ve had a loader (made by Woods for what it’s worth) that I could shove the valve handle all the way to the right - past the dump position - and it would allow the bucket to basically free fall to dump - and stay that way until I physically forced the handle back to center. Very similar to “float” on the raise/lower function. I’m wondering if the planets aligned here - do you have that feature and not know about it, did you inadvertently trigger that function, and did the handle / linkage bend or stick somehow so the handle appears to be in the “neutral “ position where it would normally be. If you do have the detent position and never used it or it’s dirty/corroded, it’s possible that it’s stuck in that position. Mine did on my stock Kubota loader - I lost “float” mode when it got water in there and corroded a bit. A little more force (toward CURL) could get it loose (or make it worse) if that’s what happened to yours.
 

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Discussion Starter #8
  • now I'm really confused I went out to verify what I said about the bucket movement from the full dump to the full curl up position. to my surprise I couldn't move it. When I lower the arms and back up and drag the bucket on the ground it will go to the curled position. Then I tried lifting the bucket arms I tried to curl the bucket and it did so I tried dumping it alittle it did but now it won't curl again it will still dump.
 

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Two suggestions:

1) Make sure your hydraulic lines are connected the way they were originally.
2) Check your hydraulic fluid level. (If it is low, add fluid, cycle the cylinders several times)

Then retest
Luis
 

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Last night while plowing snow the curl/dump function on my JD 410 loader stopped working when I was banging the bucket against the dump stop to clear snow from the bucket.
When you dragged the bucket to make it curl back, did it curl all the way back? Can you make it curl all the way back? (That takes two people, one to operate the control and the other to lift the cutting edge to rotate the bucket.)

If it won't go all the way, Powertrain is likely correct. The piston fell (or was broken) off of the rod in one of the cylinders.
 

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Discussion Starter #11
When I was looking to see what was going on it did go from the full dump position to the full curl up position using the joy stick control. But now it will only dump using the joy stick it will not curl. So it appears now there is intermittent operation that was yesterday. Today I'm going out and continue trouble shooting. Thanks for every ones input
 

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Discussion Starter #12
After looking at it again I think I can more accurately describe what is going on. Now that I have the bucket on the ground and curled up position. I've discovered there is nothing wrong with the dump function in fact it will lift the front off of the ground. The curl function is where the problem is. With the lift arms up and the bucket off of the ground if you try to curl the bucket it doesn't move and its like there is something preventing the flow of fluid because when you activate the curl function with the joy stick the engine rpm is reduced by couple hundred rpm and the bucket doesn't move. But with the bucket on the ground with lift arm down pressure the bucket will complete the curl by using the joy stick. Before I was trying to diagnose the problem with bucket in the full dump position. I don't remember now if when I was able to move the bucket into the curled position without using the joy stick or not. Guess I have some more investigating to do to get a more complete picture of what is going on.
 

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I went out and operated the loader again. It appears that the last joy stick input determines what happens to the bucket. If the last thing I try to do is dump the bucket then it holds its position and you can lift the tractor with additional down pressure. But if the last thing I tried to do was curl bucket then there is no resistance to moving the bucket to the full curl up position I can move it by hand. So it appears that the problem is either in the curl portion of the control valve or could it be in the bucket pistons. Any help would be appreciated thanks.
 

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IFF the piston is broken off... (and that is a big IF), then maybe it is getting jammed under the shaft in certain positions.

Also, if the piston were to end up back in place (ish) it might work fine when extending sometimes.

I don't know the control system well enough to say whether it could cause that problem.

At this point, I would probably disconnect one end of each of the dump/curl cylinders and see what happens when I try to extend them manually. If one of them moves freely, it is probably the culprit. If not, you haven't lost that much time or spent any money checking them.

-Luis
 

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might be something wrong internally with one of the hoses or something wrong with the valve.
Hoses are pretty easy to diagnose... Disconnect them and switch them around (note where they go! Label, label, label before disconnecting!)
They can be routed to a clean bucket to observe fluid flow, or just switch the locations of them if possible to see if the problem moves around with a particular hose. Something might have shaken loose and be lodged somewhere, acting as an intermittent check valve.

Just repeating what I've heard can happen to hydraulic lines over time. I've had the same type of problem with the flexible brake lines on my car. They collapse internally and restrict fluid flow.
 

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Ok thanks I will look at the hose connections. I looked at the male ends but not the female socket where the male end plugs in. I pushed the button on the male ends and fluid came out. If there is something wrong in the female socket then it would not depress the button on the male part. This could explain why fluid doesn't flow when I try to curl the bucket up. Sounds like something to look into thanks
 

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Ok thanks I will look at the hose connections. I looked at the male ends but not the female socket where the male end plugs in. I pushed the button on the male ends and fluid came out. If there is something wrong in the female socket then it would not depress the button on the male part. This could explain why fluid doesn't flow when I try to curl the bucket up. Sounds like something to look into thanks
Have you had the time to ck and if so have you found the problem? Be interested to know the outcome.
MikeC
 

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Discussion Starter #18
  1. I've had time to look at the problem with the bucket hydraulics. I switched the hydraulic hoses and the problem moved with the hose repositioning. I think that I understand how the fluid is directed through the system. I have been reading the manual and it seems that the fluid in the curl/dump circuit is directed to flow through one of the two hoses that are connected to the SCV and the top and bottom each end of the hydraulic cylinders. The direction of fluid flow out of the hose to dump the bucket goes to the top of the cylinder and extends the cylinder and the fluid in the cylinder that is displaced by the cylinder extension flows back to the other hose connection on the SCV. If the bucket is curled to the up position the fluid flows in the opposite direction in the bottom connection and out the top and back to the SCV. I'm restating the problem that I'm experiencing with bucket in the curled up position I can dump the bucket I can even lift the front end off the ground. But when I try to curl the bucket up its like something is stopping to fluid flow the engine RPM is reduced slightly and the bucket doesn't move. But with the bucket on the ground and with down pressure on the bucket I can get the bucket to the curled up position by trying to curl it with joy stick. The bucket will move to the half the dump position when the arms are lifted. Since the problem moves with switching the hoses I think that rules out the SCV. I've inspected the male and female QD's and I don't see anything wrong with them. I've tried to lift the bucket from the mid dump position by hand and I'm unable to move it. I don't have any explanation as to how the bucket can move when it is lifted off of the ground. I guess I either have a cylinder problem or a hose connection issue but I don't know how to continue with the diagnosis. I would appreciate any input thanks.
 

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Hoses have been known to fail internally. The inner liner gets separated at the termination and forms a flap which impedes flow in one direction and not the other.

Disconnect the two suspect hoses from the loader end leaving the ends at the valve connected, place the free ends in a clean container and start the tractor at idle. Cycle the valve each way and observe the flow from each of the hoses into the bucket. If both flow correctly, flip the hoses end for end and try again.

Replace the hose that has the least flow.
 

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Discussion Starter #20
A couple more observations; After using the SVC to dump the bucket If I use down pressure from the lift arms and using the SCV to curl the bucket it can be raised to the full curled up position. When the lift arms are raised the bucket will no longer stay in the curled up position in fact it will fall to the full dump position and can be moved up and down from dump to curl position by hand. Which I think indicates there is no fluid in the cylinder. But if I use the SCV to dump the bucket it develops down pressure that lifts the front of the tractor off of the ground. But if I raise the lift arms the bucket will fall to the full dump position. Does this indicate that there is no fluid in the curl section of the cylinder the other question is why does the dump portion of the system work and other times there is nothing there. It will all ways pressurize the dump cycle and never the curl. I will still try disconnecting the two hoses check the flow. As always thank you for your input.
 
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