Bobcat 763 hydraulic flow

Hi all, I have a Bobcat 763 G-Series and have made a brush cutter for it. I feel like I’m not getting the proper hydraulic flow. This is the first aux attachment I’ve used with this machine. I notice in my upper left control panel it has a variable flow and a maximum flow only button. I’ve used both and there is no change in hydraulic flow. Am I missing something? I plan on putting a pressure gauge on the hoses to see if I’m getting proper pressure.