My bucket is floppy.

[Zephrant]

One thing more to note- the main rams do it. I can set the bucket down, then push hard down on the bucket, and it takes several seconds before anything happens.

So either it is all the rams or something that is common with them (like air in the linds).
I have 800 hours on the tractor now, 750 with a prior owner that at least did not take care of the paint well.

Would cylinder scoring be obvious or hard to see without taking things apart?

 

[jinman]

One thing more to note- the main rams do it. I can set the bucket down, then push hard down on the bucket, and it takes several seconds before anything happens.

So either it is all the rams or something that is common with them (like air in the linds).
I have 800 hours on the tractor now, 750 with a prior owner that at least did not take care of the paint well.

Would cylinder scoring be obvious or hard to see without taking things apart?

Cylinder scoring is impossible to see without complete disassembly and inspection.

I'm really astounded that you say it takes several seconds to respond. If you said a moment, half a second, or even a second, I could understand that, but you say "several seconds," and that seems an eternity to me for hydraulic response.

If you system only pumps 5 gallons per minute, in one second, it should pump 1/3 of a quart of fluid into the cylinders. In three seconds, thats a full quart of fluid and probably is all the fluid it takes to extend both cylinders at least 5 or 6 inches. It just doesn't make sense to me that you could have anything causing such a delay without a huge leak somewhere.

EDIT: Since you say both lift and curl do this with the bucket sitting on the ground, I don't think cylinder scoring is your problem. It almost sounds to me like you have a delay in the open center system closing to apply pressure through the joystick. If you have something sitting on the ground on the 3PH and raise the lift lever, does it also have a delay of several seconds before the lift starts up? If it does, the whole hydraulic system is responding slowly.

 

[J_J]

Zephrant has not connected a gage to the pump, and therefore has no idea of the original pump pressure. If the pump is pumping at the rated pressure, and the lines and cylinder is full of fluid, then as soon as the valve is activated, something should start to move. I don't believe he said he had made the valve go into relief yet either. With all power off, can you shake the bucket by hand? Is it loose in any way. If you say it flops back and forth about 5 in, then something else is wrong. Pins, bushings, etc.

 

[Zephrant]

The 3PH raises instantly- in fact it comes up so quickly it is hard for me to raise it just a 1/2" when I'm trying to grade with the blade. Down is gravity controlled on this unit, so also has no delay.

When I say "several seconds" I mean that it is 4-6 seconds when the tractor is at idle, and 2+ when at full throttle. I normally work around 2000 rpm, not at full throttle.

I did gauge the pressure last spring- it was within range then, but I'll do it again and see what it says.

So I just went outside in the cold (32 degrees) and dark to time the delay exactly. I warmed up the engine for about 1 minute, then went full throttle. The system was flawless- no delays, moved fast, no issues at all.

So either being cold or sitting for 24hrs makes the problem go away.

How would I tell if I was getting air bubbles in the fluid? It's pretty tough to say just from the little sight glass.

Next time I can run the tractor for a while I'll test it when I first start out, and again when I'm done for the day and it is all warmed up.

Thanks a lot for the help all- I appreciate it-

Zeph

 

[DEON]

Zephrant, I previously owned a Kubota B1700. The loader did just what you are explaining. If I pushed down to back drag, then lift the loader arms, the bucket would flop down. I could get off the tractor and rotate the bucket about 1/3 of it's rotation by hand with absolutely no resistance. I brought it to the dealer, under warranty. They tried everything with no results. I finally asked to try out a same tractor on the lot and that one did the same thing. I test drove a L3010 and that one worked well. We removed the loader control from the L3010 and mounted it to the B1700. It fit perfectly but had a longer lever. The problem all but disappeared. Only occasionally noticed it a very slight bit from then on. Kubota tech support gave them permission to leave the control valve on my machine so it is still on it today. The valve worked faster and probably allowed oil to fill the back side of the cylinder in due time to solve the floppy cylinder syndrome. I now own a Kioti CK25. I have noticed this on the CK but only very slight and very occasionally, probably when running at to low rpm.

 

[Zephrant]

DEON- That is exactly what I see too.

I guess I'm becoming convinced that it is inherent in my system, and that there is no easy fix. I've considered replacing the loader control before because the linkage are worn out and it makes the lever sloppy.

Thanks for your post!

 

[J_J]

There is something that isn't making sense here. If you raise the bucket up and down about four times, and leave it at about 4 ft off the ground, then go to the bucket and try and shake it while observing the cylinders. Is the bucket only moving, or is the bucket and cylinders moving?

 

[J_J]

On your valve, can you observe if the spool is moving when you are moving the levers. Just how loose are the levers?

 

[Zephrant]

JJ- The bucket is solid if I do that test at full throttle. Just a little rattle/slop from the pins. I'll test again this weekend though, also at idle.

The levers are pretty sloppy- I'll measure a little and post tomorrow.

 

[Zephrant]

Well I finally made a connection- when I load the bucket with gravel then dump it, the bucket is very floppy - I can move it by hand and see the cylinders move in/out several inches. When I go full dump and hold it for 3+ seconds (until the engine lugs) it is fine again.

Without a load in the bucket, it is pretty clean- no issues.

So as mentioned above, either air or vacuum is behind the cylinders, making it mushy.