How to Tell If Hydraulic Oil Has Water in It

Hydraulic oil, commonly referred to as hydraulic fluid, is used in automobiles, fork lifts, industrial machines and airplanes according to the Agency for Toxic Substances and Disease Registry. Since water in hydraulic oil causes the formation of emulsions which then leads to corrosion, testing the oil is an important part of regular maintenance. Additionally, water in a machine's hydraulic fluid often indicates a mechanical issue. A so-called "spat" test helps you determine if water is in the hydraulic oil.

• 1

  Plug a laboratory hot plate into an electrical outlet and set it to medium-high. Heat it above boiling, but below 350 degrees.

• 2

  Take a sample of hydraulic oil from the bottom of the reservoir to obtain a more accurate reading; since this is where the water settles after separating from the oil.

• 3

  Place three or four drops of the hydraulic oil you are checking for water content on the hot plate.

• 4

  Watch for bubbles and listen for a sizzling noise. If it bubbles or sizzles, there is water in the hydraulic oil. Pure hydraulic oil will thin out, but not make a noise or show signs of heating up.