445 hydraulic problem

If by the 3pt working fine you mean that it raises a load at a reasonable speed and holds it there that tells you that the pump is likely working OK and at least the 3 point spool and cylinder are OK.

The loader bucket only raising 2ft or so likely means that it raises to that point before all the oil in the resevoir is used. Are the main lift cylinders one way or two way?

Lowering back down immediately when you let go of the lever is another problem. The most likely problem is that that spool is not centering properly. You can check it by holding the lever slightly off of the center position one way or the other. One way the loader will likely drop faster. The other way it should hold the loader in position. I'm assuming the centering springs on the remote levers are not broken and are doing their job properly. If one of the spools need to be centered, you will need to take the system apart. An I&T manual has a setup procedure that is pretty good but if you have specific questions feel free to ask.

A 445 won't make most loaders operate very fast but will work satisfactorily other than being somewhat slow. IF your main lift cylinders are only one way, the system likely won't have enough fluid capacity to operate them.

John Kinsey