I've got a little 6hp pressure washer. Water goes in, water comes out. Simple. The pump died, and I was debating buying a new one until I came across a 16hp Landa at a yard sale for less than what a pump would have cost for my other one. Now I want to make sure I don't screw this thing up, since it's got more hoses and valves on it than I can figure out. I tried punching the model number into google (PGS5-35221)and got sorta close, but nothing definitive. I'm going to try and post pics. We'll see how it goes. This is the pump layout This is the water inlet side. I need to know first of all what the threaded inlet (or outlet) is above the hose. It's got a valve to open or close it. I assume it's an inlet for soap or other chemicals. Also, the knob on the unloader valve is adjustable. Is this for adjusting pressure? And what's the green knob for? I haven't tried to turn it. Does it do anything, or is it just a cap that happens to be green? This is the other side. What does that valve with the yellow handle control? Like I said, I don't want to blow this up. Probably expensive to fix. Any input appreciated.