L45 TLB Curl Cylinders Bleeding Down

[KubotaToy]

I just noticed today that my curl cylinders bleed down rather quickly, like 10 sec from level to completely down (but they only do it from level if I put the bucket at a higher angle I do not seem to get the same bleed down). I only have 200 hours on it and would not expect the curl cylinders need a rebuild but maybe I do. I have worked it hard over the past few years clearing my property.

Question for you hydraulic experts, could there be something else causing this?

 

[boggen]

which one of below not a clue... maybe something will click.

1. ballooning. so much pressure / stress may cause the cylinder to "balloon out" in the center. and allow oil to flow around inside the cylinder
2. seals inside the cylinder are bad.
3. valve is bad ((internal seals, spool valve itself, relief valves on given spool sticking))
4. putting valve into regen or float mode possibly. ((perhaps FEL arms and bucket hooked up to opposite ports on joystick))

guessing about only way you are going to get down to figuring out if cylinder/s or joystick / spool valves. is with a couple pressure gauges hooked in line between things. so you can actually get a measuring of things and figure out were something might be happening.

 

[Deere Dude]

I had 2-400 hours on my JD FEL and acted the same way. It got worse in time to where it would need to constantly be picked up. For me the easiest solution was to just rebuild the cylinder and hope that was it. It was.

 

[rScotty]

I just noticed today that my curl cylinders bleed down rather quickly, like 10 sec from level to completely down (but they only do it from level if I put the bucket at a higher angle I do not seem to get the same bleed down). I only have 200 hours on it and would not expect the curl cylinders need a rebuild but maybe I do. I have worked it hard over the past few years clearing my property.

Question for you hydraulic experts, could there be something else causing this?

Sounds like you are getting some good advice. All of that is right. Could be in the operating valves, relief valves, or even in the construction of the cylinders themselves. There are ways to test the various parts to get closer to where the problem is. But all the ones I can think of involve putting high pressure valves in line with the hoses to selectively block off hydraulic lines to see what is happening. Or at least undoing the line and capping it. Really messy work. And it is greatly helped by having a basic piece of shop equipment that at least measures pressure and hopefully flow too.

How much do you want to get into it? None of the diagnosis is really hard to do if you have basic hydraulic knowledge. But that one gauge tends to be expensive, and no matter what you do it tends to be very messy.

I can't think of a simple test to do without disconnecting anything that would isolate the curl cylinders all by themselves. Can anyone else?

What you are seeing isn't right. My M59 has pretty much the identical hydraulic system and the curl will stay without moving for hours. Even with a moderate load in the bucket.
Luck,
rScotty

 

[KubotaToy]

It has got worst. They will not stay up at all today, almost impossible to carry anything had to hold the curl up position on the loader control constantly. One thing I noticed, I can drive the bucket down to the stops and it load the pump and hear the relief lift and it will hold the tractor up, when I drive it up against the stops, I hear loud leakby and it takes a while for the relief to lift and when I let go, it drops. That makes me think it maybe it is the curl cylinders that need rebuilding. I have rebuild kits already, I had to rebuild one of the lift cylinders due to the outer dust seal tear and the dealer was adamant I rebuild both. He ordered kits for the curls vise the lift and just gave me the curls since the lift kits were like 97.00 a piece. I will do that this week and see if that is the solution.

I do not mind building a test rig, not sure what I need.

 

[KubotaToy]

Update, I finally found time to rebuild the cylinders, yep, the internal seals were toast on the left curl cylinder. They only lasted 189 hours. All better now. My dealer also build me a test gauge and gave me a three test locations to record the pressures, he offered if they are low, bring it in and they would adjust for free (bought it from them over 3 years ago, seems like a good deal).

 

[mike69440]

No way the seals go that quick

Not installed correct from the get go.

I have 10x the hours you do and leakdown is still technically within allowable specs, but they are starting to leak down a little.

Set your pressures at 2750 psig.