I know this is an old post, but I recently bought a used 3520CX with a BL25R loader.Just an FYI, If you push the the FEL stick all the way forward you will find it will stay there.
This is called "Float Position".
It lets the bucket float in the all the way down position and I use it for back grading/smoothing.
I even tilt the bucket so the front of it is doing the grading.
It lets the weight of the bucket do the work.
When I try and lower the bucket and tilt is some to back drag the tilt cylinders will float some .
So if back drag over a slight pile of dirt it will just float over it. It doesn't level it. Just curls the bucket as I back up.
Is this normal? The dealer told the previous owner this is normal and you have to hold the valve over and build up pressure?