The other day, I was getting pretty substaintial pump chattering (sounded like the pump was cavitating or there was air in the system) on the last lawn of the day. That night I unscrewed the hydro tank cap and looked to see what the oil level was. I looked inside and all I see is a screen inside. So I grab my owners manual (what a disappointment by the way) to see what the level is supposed to be. They say: "Fluid level should be 1" from top of reservoir" Is that 1" from the bottom of the screen? Or 1" from the top lip where the cap seals? Mine, like I said is just barely getting the bottom of the screen wet. Is that level 1" too high, or 1" too low?