(1) Check the fluid level.
(2) Check the breathing valve cover, breathing valve filter and injection filter screen - do not punch holes in the filter screen to avoid too fast refueling.
(3) Check the filter indicator and/or differential pressure gauge.
(4) Visually inspect all system hoses, pipes and pipe joints for leaks and wear.
(5) Check the system temperature by built-in thermometer or handheld infrared detector.
(6) Visually detect whether there is aeration inside the oil tank: aeration refers to the situation that discrete bubbles enter the oil tank when the oil enters the hydraulic pump.
(7) Listen to the cavitation of the pump. Cavitation is slightly more complex than aeration, but the two have few similarities. How to distinguish aeration and cavitation? One method is to install a vacuum gauge on the suction side to ensure that the pressure is equal to or greater than the value specified by the pump manufacturer. Foaming in the tank is usually a sign of aeration.
(8) Sample to check for signs of fluid color, contamination, and odors. Note that visual inspection is limited to detecting signs of excessive contamination.
