Soggy Bucket Issue

[twisted]

Good day to all.:newhere:

I made this post earlier but it went on the new member page (which I am). I have a 2004 New Holland TC55DA with an 18LA loader attached. I recently had a problem with one of my bucket cylinders which has been repaired but now my bucket won't stay where I put it. It droops down rather rapidly. I rebuilt both bucket cylinders using new parts from NH. I am a mechanic by trade and am confident with the repair and subsequent bleeding of the hydraulics even though I understand they are self bleeding. I understand this is not an unusual issue but so far haven't been able to read on here what the "FIX" is. Any suggestions will be appreciated. Thanks:drink:

Twisted

 

[J_J]

Did you bleed the hyd system?

Just cycle all cyl about 10 times.

 

[oldnslo]

Sounds like your control valve is leaking. Do you have quick disconnects in the lines? If yes, lower the loader so the bucket is resting on the ground, unhook the bucket quick disconnects. Raise the loader, does the bucket still dump? If yes one or both of your cylinders are leaking. If no, the control valve is leaking allowing the bucket to dump.

 

[twisted]

Sounds like your control valve is leaking. Do you have quick disconnects in the lines? If yes, lower the loader so the bucket is resting on the ground, unhook the bucket quick disconnects. Raise the loader, does the bucket still dump? If yes one or both of your cylinders are leaking. If no, the control valve is leaking allowing the bucket to dump.

I have disconnected the lines at the quick disconnects and raised the lift and the bucket leaks down but then when I lower the bucket back down to the ground and allow the weight of the tractor to rest on the bucket (which should push the bucket back up) it holds fine, it seems that it is leaking one way but not the other.

 

[twisted]

I suppose I'll have to re-lick this calf!!! Thanks y'all:confused3:

 

[Dave M7040]

Does the internal piston slide unto the cylinder push rod and be held in place by a large nut?
If so there will be a small o-ring to seal between the piston and the push rod. These are prone to failing and then allow leakage from one side of the cylinder to the other.
Re your test with quick disconnects unhooked. Imagine the cylinder at half stroke. The two halves of the of the cylinder do not hold the same volume of oil because the push rod will displace oil and result in the outer half of the cylinder holding less oil than the rear half of the cylinder. I suspect that this fact can make your test perform differently when your bucket is lowered to the ground because at some point there is not enough room for the oil being displaced from one half of the cylinder to the other.
Dave M7040