Pump pressure is regulated by 2 relief valves in the hydraulic valve body for lift, tilt functions. Second is accessories. First pressure is main for lift and tilt. Should be around 2450psi. There are ports in the valve body to do so. Depends on your make of valve. If no ports visible. Remove 1 line of tilt on valve body and connect your gauge there. Remember safety with fluids. Once your gauge is attached you can get pump psi. Again type of valve body and relief valve is also needed to be known. Some have 1 relief valve but is stacked to adjust both primary and secondary psi. Others have upper and lower relief valve.