What causes my gauge to fluctuate and the pump to act erratic after I clean the filter, or when the machine has not been used in a while?
This is caused by air in the system. With machine running; Turn the pressure control all the way down and let the pump move liquid under no load conditions, then gradually increase pressure to normal settings. Note: Small amounts of air will bleed through the hydraulic agitator (if equipped and not clogged). The pump still has a surge after correcting air-damper pressure and cleaning the agitator. The next step is to check the pumps intake and exhaust valves. A small particle stuck between the valve and seat or broken valve spring will cause surging. Check one at a time and be sure to note which way valve is positioned.
