Are you adjusting tire pressure, hydraulic pressure, turbo boost, air ride seat, operator station barometric pressure?
Let’s assume you want to increase hydraulic pressure so you can lift more and break the loader or front axle bearings: I’m not sure there is an adjustment screw. You likely have to modify the safety relief valve that prevents the system from blowing up so that it opens at a higher pressure. Add shims or a different spring to the valve. Good luck!