Loader My loadeer seems to be a little weak

[Looking4new]

Late to the party as usual....but what and how are the cylinders drifting?

Are they extending or retracting?

You are saying that if you leave the loader suspended....that it both drops the loader AND dumps the bucket.
1. The lift cylinders will now allow this to happen. Thats in the valve. As those cylinders are COMPRESSING....which CANNOT and WILL NOT happen unless fluid EXITS the cylinder
2. The curl cylinders are EXTENDING. This can happen either due to a valve OR the piston seals.

In your last scenerio....lifting the front of the tractor and not holding it in the air
1. The lift cylinders are now EXTENDING....which again...and EXTENDING cylinder can either be the cylinder seals OR the valves
2. The curl cylinders are now trying to COMPRESS. Which cannot happen due to seals. That indicates a valve.

So I am having a hard time following just what is going on.

It seems as if none of the cylinders will hold in ANY direction....either extension or retraction. Which points to a VALVE and not the cylinders.

Without more understanding or troubleshooting, I am afraid you are just going to waste your money rebuilding or replacing cylinders.

The lift cylinders stutter and stumble when lifting and so do the curl cylinders. Often I have to return the control valve to the neutral position and then try again to get it to lift or curl.
I will get the hydraulic shop 5 miles down the road to sort it out in Spring. Right now (winter and snow) it still works, more or less.