Judging the quality of hydraulic oil

The quality of hydraulic oil is crucial for the maintenance of a vehicle. Here are several methods to determine the quality of hydraulic oil for you.

The determination of moisture in oil

Rupture test: Heat a thin piece of metal to 110 degrees Celsius and then drop a drop of hydraulic oil. If the oil bursts, it indicates that there is more than 0.2% water content in the oil.

Judgment of appearance color

If the hydraulic oil appears milky white and cloudy, it indicates that there is water in the hydraulic oil. The hydraulic oil appears blackish-brown, indicating that it has been oxidized at high temperatures.

A simple judgment of viscosity

Glass tilt observation method: Place two different oils on a tilted clean glass and observe which one flows faster, indicating a lower viscosity.

Oil droplet spot test for oil contamination

Take a drop of the tested hydraulic oil on the filter paper and observe the change of the spot. If the hydraulic oil spreads rapidly and there is no sediment in the middle, it indicates that the oil quality is normal. If the hydraulic oil diffuses slowly and sediment appears in the middle, it indicates that the oil has deteriorated.