FELL Bucket curls back very slow

[wagne223]

My guess would be you are looking at more the seal damage. Likely the rod is bent, or the piston is damaged, or both.

If that is the case, those items are probably dragging on the bore causing the slow movement.

I would have had both those cylinders torn down prior to replacing that pipe.

I recommend you do that now.

 

[lzicc]

These are my thoughts and I could be totally off. If it was bent, it would curl slow both ways. It only curls slow when I curl back. I tested the curl back under load and even though it is slow, it hasn't lost any strength or does it leak down, so that is why I am questioning the seals being bad. I seems like there is a blockage somewhere and it's got getting the fluid fast enough when curling back.

The OEM steel line will be delivered today. I want to get that on so I can get that out of the way. When the hydraulic place made the line, they had to use elbow fittings for the tight corner bend. Sometimes I wonder if that fitting is a bottleneck for the flow of fluid since it would reduce the inside diameter of the line at the elbow. I know, I am reaching.

If you look at the picture below, line 50 is the one that burst and was made by the hydraulic shop. If you look at my arrow, it points to a 90 degree bend. They could not make that bend because the fitting next to it was too close, so they used an elbow to make that bend.

 

[BukitCase]

Your comments about swapping hoses leads me to think you may have quick disconnects on your FEL lines - if so, the symptoms MIGHT indicate a broken spring inside one of the QD's - if this happens in a QD pair, they can start acting like a 1-way CHECK VALVE (albeit a "leaky" one, therefore slow instead of stop)

BTW, this is NOT "internet fact", I've personally had it happen on two different occasions in the past 10-12 years; so, not "common", but possible...

If that's what happened, it could either have been CAUSED by the overpressure (aided by faulty materials in the spring) or it could be entirely COINCIDENTAL. ("stuff happens")

You may be able to check this fairly easily by powering down, wiggling all levers multiple times, and separating the QD's one pair at a time, then pushing on the center (ball or poppet) - do NOT do this with a body part, even a powered down hydraulic system can inject fluid into your body - use a small nut driver or similar.

Once any pressure is relieved, if the ball or poppet moves without quite a bit of force (or at least DIFFERENT than its mate) you might have found your problem.

I personally am NOT a fan of REGEN, my opinion (at least for non-commercial operators) is that it's more of a PITA than a help (especially if you wanna add a diverter to that circuit). If ya can't wait a couple more SECONDS for a bucket to dump, try using a pick and shovel instead - I bet you'd change your mind pretty quick

Anyway, it's another (cheaper) thing to check that may help, definitely worth the time it takes to check it out... Steve

 

[lzicc]

I disconnect both rams from the bucket and cycled them back and forth. Both rams were both very slow moving back. What are the chances that the seals in both cylinders blew? I wonder if the issue could be in another part of the system. I did remove the QD's and was able to push the ball on both and they both reacted the same. I also visually looked at both cylinders and they both look true and straight.

 

[BukitCase]

If you can (and haven't already) swap your QD's so "curl" = "dump" (assuming regen doesn't keep that from working) - and see if "extend" becomes the slow one - this might tell you more about what/where the problem is. I've seen things come loose in hydraulic systems that can ALSO act like a check valve, and your mishap could possibly dislodged something that's been in there since manufacture, either in the control valves, an inline fitting, or??!?.

It does seem a little odd that BOTH cyls would've failed at the same time; usually the weakest link gets hammered first, but anything is possible. Remember, troubleshooting is almost ALWAYS just "finding out all the things it's NOT"... Steve

 

[oldnslo]

Iz
Have you tried feathering the curl function to see if the cylinders retract smoothly. Try slowly increasing the retract speed to see if you can or see a change in speed or in the hoses that would indicate pressure building. If yes then I would also suspect a failing quick disconnect half. Either half can fail.

Sometimes they will work at lower flows and then act like a restriction at higher flows

Seriously doubt new tune is the problem since the Dump function works correctly

 

[lzicc]

I did swap the 2 QD. Once I did that, no matter which way I pushed the lever, it would dump. Weird. I'm tempted to remove one of the lift cylinders and replace one of the curl cylinders with a lift cylinder and see if it goes back slow also. I wouldn't connect it to the bucket, just the actual hydraulic lines. I want to try to pinpoint where the issue lies. If the lift cylinder acts the same way, then I know that the curl cylinders are good and the problem lies further back in the system. In my opinion, it seems like there is blockage somewhere in the hydraulic system only for that circuit. I did check the UDT fluid level again and it is full.

If you can (and haven't already) swap your QD's so "curl" = "dump" (assuming regen doesn't keep that from working) - and see if "extend" becomes the slow one - this might tell you more about what/where the problem is. I've seen things come loose in hydraulic systems that can ALSO act like a check valve, and your mishap could possibly dislodged something that's been in there since manufacture, either in the control valves, an inline fitting, or??!?.

It does seem a little odd that BOTH cyls would've failed at the same time; usually the weakest link gets hammered first, but anything is possible. Remember, troubleshooting is almost ALWAYS just "finding out all the things it's NOT"... Steve

 

[lzicc]

I can try that tonight.The cylinder does move smooth, it's just very slow.

Iz
Have you tried feathering the curl function to see if the cylinders retract smoothly. Try slowly increasing the retract speed to see if you can or see a change in speed or in the hoses that would indicate pressure building. If yes then I would also suspect a failing quick disconnect half. Either half can fail.

Sometimes they will work at lower flows and then act like a restriction at higher flows

Seriously doubt new tune is the problem since the Dump function works correctly

 

[ruffdog]

I did swap the 2 QD.

Have you tried switching the loader lift QD's with the loader curl QD's? It might tell you if the problem is the valve end or the bucket end.

 

[lzicc]

I tried that too and it didn't work right so I could not tell.

Have you tried switching the loader lift QD's with the loader curl QD's? It might tell you if the problem is the valve end or the bucket end.