JD 350B Slow hydraulics

I have a JD 350B. Recently I have been having problems with my hydraulics being slow, and I believe loss of power. The motor does not load up when I bring any of the pistons to full extension or retraction. The filter was replaced about a month ago, and the hydraulics worked okay after the filter change. I just got this machine, so I am not sure if they worked as they should have, but they worked much better than now. I am using JD oil. At a quick idle, the hydraulics will not move the bucket (this is a loader). I need to set the throttle at about 1/2 to get an empty bucket to lift or return from the dump position. I have a backhoe as well and the piston that moves the entire boom up and down behaved the same way. Not sure about the other ones, really did not test them before taking the backhoe off. There are no external leaks that I can find. So I am thinking I have a problem with a relief valve or the pump. Any ideas on how to figure out what is actually causing my problem?

The pump does not appear to be making any strange noises and it is not getting hot. After using it for a few hours I can still touch the pump without getting burned.

Thank you for any help,

Paul