John Deere 300CX 4in1 Loader operation

[bramleyestate]

Hi I have recently purchased a JD 4400 Tractor 900hrs with 300cx 4in1 loader fitted. This uses the electric button on the loader lever to operate the 4in1. When I push the lever to the right a little it opens the bucket, if I continue to push to the right it then annoyingly closers the bucket. I would like to know if this is how JD have set it up, or whether as I suspect another issue? The bucket closes properly if I move the lever to the left. Of note I am sure on a couple of occasions it did work correctly. I have noticed that when I curl the loader bucket pushing the lever to the right again, it appears to temporarily stop at the the same point I am having the 4in1 bucket change direction! Also experiencing heavy power steering at low - middle RPM??
I look forward to your replies, many thanks Jules