I bought a used Ridgid pressure washer model RD80746. The pressure washer works great but to me it doesn't feel like it's putting out the 3000 psi it's rated at. It has the axial pump on it and im considering just buying a new pump for it. Im not sure if the pumps actually wear out to a point that they loose pressure but when operating the gun doesn't push back with much force. I've noticed also when cleaning wooden porches or concrete I have to keep the tip about 2 inches from the surface to clean it good. Is there a way to test the psi output? If I buy a new pump what else will I need to make it work?