Green Tractor Talk banner

1 - 17 of 17 Posts

·
Registered
Joined
·
17 Posts
Discussion Starter #1 (Edited)
Hi all,

I often use this site as a resource for how to's and don'ts and I can't find the answer to this one. It's a strange one. My left curl supply line blew out the the other day. Thankfully I had my shades on and still have my eyesight, but I got soaked none the less. Anyways, I replaced the line this morning and all was working well. I cycled the bucket about twenty times to work the air out and everything seemed in order. However, later this afternoon after brush hogging and moving some stuff around, the down curl function is messing up. If I feather down lightly the bucket goes to full extend (which is normal). Under full down (stick far right), it goes down like it normally should, then extends down until I feather back to about half way ish.

Retract (up) works just fine. Curl down works under light feather, but moves up as soon as I go far right on the stick. I can hear the engine strain a little as it's curling down. No strain when retracting the pistons in full up at any speed.

So, what the heck is going on here? Is it air in the system from the line I had just replaced? I never had this problem before and it's got me scratching my head. Weird part is, it was all working fine initially, then a few hours of work later, it's acting up.....

Added: Also once I replaced the line, I washed the crap out of it to get all the oil off it with a regular garden hose and soapy water. Made sure I didn't directly blast any electronics or anything. Not sure if this has anything to do with it, but I figured I'd add it in. To me this sounds like a hydro problem and nothing electrical was wrong after the initial wash.

Thanks in advance for any and all replies.

Kevin
 

·
Premium Member
Joined
·
2,010 Posts
It sounds like you have the bucket roll up and bucket dump QC's reversed.

I'm not sure but it sounds like you are getting into the regen section of the valve (far to the right).
 

·
Registered
Joined
·
17 Posts
Discussion Starter #3
I never had the QC's off....

It sounds like you have the bucket roll up and bucket dump QC's reversed.

I'm not sure but it sounds like you are getting into the regen section of the valve (far to the right).

I never had anything apart other than the line that blew out on the FEL. I took a video and will post as soon as it processes.
 

·
Administrator
Joined
·
17,046 Posts

·
Registered
Joined
·
17 Posts
Discussion Starter #6 (Edited)
What were you doing when the line blew? There is a good chance if the circuit was over-pressured enough to blow a line, a cylinder is damaged too, or at least the piston seals.

When pushing the joystick far right, your in the regen or "fast dump" mode and both hoses are pressurized, then could cause what your seeing if one cylinder is bypassing.

https://www.greentractortalk.com/forums/hydraulics/749-what-regen-regenerative-function-front-end-loader-valve-read-here-;.html
I was pushing a brush pile back into huge brush pile I had ben dumping into. I had the forks pitched down, so the forks were pointed at the ground while doing so and kinda gave it a running start. The line went bang and then I just drove it back to my garage. Crazy part is, after replacing the line everything seemed to be working in order. I had the SCV lock lever in the fully unlocked (Top position for regen mode). I'll have to check again, but I believe when I moved the lock lever to the middle position (non regeneration mode) it worked as normal.
 

·
Administrator
Joined
·
17,046 Posts
Ahhh, yes, sudden and dramatic over-pressurization of the system. I’ll bet $5 at least one cylinder is compromised, but they are best rebuilt in pairs anyway.
 

·
Registered
Joined
·
17 Posts
Discussion Starter #8
Ahhh, yes, sudden and dramatic over-pressurization of the system. I’ll bet $5 at least one cylinder is compromised, but they are best rebuilt in pairs anyway.
Thanks Ken! Appreciate your insight!

If it's just the cylinder(s) that are messed up, I'm good with that. I can't afford a SCV replacement and was hoping it wasn't anything to do with that part. I will probably rebuild them myself at some point in time, but I can still use the loader for what I need in the mean time.

Once I get to them, I'll follow up on the outcome.

Thanks again,
Kevin
 

·
Administrator
Joined
·
17,046 Posts
Kevin, try swapping your dump/curl hoses for your lift/lower hoses and see if the problem basically stays the same.
 

·
Registered
Joined
·
4,425 Posts
The SCV can be rebuilt too, by the way.:good2:
 

·
Administrator
Joined
·
17,046 Posts
The SCV can be rebuilt too, by the way.:good2:
Do tell please?

JD shows no parts breakdown for them, and the spools are a matched set to the valve bodies so they can't be replaced.
 

·
Registered
Joined
·
17 Posts
Discussion Starter #12
Kevin, try swapping your dump/curl hoses for your lift/lower hoses and see if the problem basically stays the same.
Once swapped, if the problem DOES NOT follow, then I know for sure its the cylinders....however, if it does, that's no bueno and something is up with the SCV. I think I got this for now hopefully.

Again, thank you!!! I've been reading a ton on how these hydro systems are supposed to work and your help and links to good discussion has been VERY informative!!!! I'm no expert by any means, but I know enough to make me dangerous and figure this one out I think : )

Kevin
 

·
Registered
Joined
·
4,425 Posts
Do tell please?

JD shows no parts breakdown for them, and the spools are a matched set to the valve bodies so they can't be replaced.
Just going from what i've read in my 4510 (father of the 3x20 series) TM.
 

·
Premium Member
Joined
·
2,010 Posts
I was pushing a brush pile back into huge brush pile I had ben dumping into. I had the forks pitched down, so the forks were pointed at the ground while doing so and kinda gave it a running start. The line went bang and then I just drove it back to my garage. Crazy part is, after replacing the line everything seemed to be working in order. I had the SCV lock lever in the fully unlocked (Top position for regen mode). I'll have to check again, but I believe when I moved the lock lever to the middle position (non regeneration mode) it worked as normal.
As Kenny has said, you most likely have a damaged cylinder internally along with the combination of you moving the lever to regen, the condition that you are seeing is what will occur. If enough pressure is created to blow a hose due to over pressure, you will most assuredly damage a cylinder also.

Every FEL user should be aware, when levering things with the FEL bucket or forks, you can apply an extreme amount of force on the bucket roll cylinders and maybe even the FEL lift cylinders. This excessive force translates to dangerously high pressure inside the bucket roll cylinders. This can occur because there are no port reliefs on the SCV on these tractors. This simply means, when this increased pressure occurs due to the leverage forces that you are applying by propelling into the bucket or forks, there is no way for this dangerously high pressures to relieve. The oil is locked in the cylinder until the pressure gets so high, something breaks or blows.

Two things can happen when something breaks, if the cylinders are partially extended, most likely a hose will blow and/or damage to the cylinder will occur. If the cylinders are extended all the way (bottomed out), then a cylinder rod will break or a head gland will get blown out of the cylinder.
 

·
Registered
Joined
·
17 Posts
Discussion Starter #15
Kevin, try swapping your dump/curl hoses for your lift/lower hoses and see if the problem basically stays the same.
So interesting enough. The problem got a little worse as I used it the other day and I was certain something was seriously messed up. I swapped the lines and the problem followed, but it gradually got better. I cycled it for about 10 minutes this way and it was getting better, but still being weird when I engaged the regen mode of the SCV, however all pistons fully extended and retracted so it was an improvement. When I would go to regen (full right stick), the bucket would stop momentarily and then continue. Making progress though.

I swapped the lines back and ran it for another 10 minutes, then swapped them again and cycled them for another 10 minutes and everything seemed fine. Swapped lines back to original lastly, put the bucket on and ran it flawlessly for another 10 minutes. I think I'm GTG.

I suppose it was air trapped in the system, stuck valve that unstuck in this process? Anyways, I'm a happy camper now and need to thank all for me having to research the hydro system (schematics and theory) to learn about it, Ken for the line swap idea, and all who have contributed to the hydro forum as I read countless threads here : )

I'm stoked that I'm back in action!!!!! Thanks GTT!!!!

Kevin
 

·
Administrator
Joined
·
17,046 Posts
Wow good luck Kevin :thumbup1gif:
 

·
Registered
Joined
·
17 Posts
Discussion Starter #17
Thanks

Wow good luck Kevin :thumbup1gif:
However, I'm happy it's working fine right now not under load, but I'll see how it goes once I use it again in the ensuing weeks. I'll keep my fingers crossed that it doesn't return.
 
1 - 17 of 17 Posts
Top