Wikipedia
Hydraulic fluid(s), also called hydraulic liquid(s), are the medium by which power is transferred in hydraulic machinery. Common hydraulic fluids are based on mineral oil or water. Examples of equipment that might use hydraulic fluids include excavators and backhoes, hydraulic brakes, power steering systems, transmissions, garbage trucks, aircraft flight control systems, lifts, and industrial machinery.
Hydraulic systems like the ones mentioned above will work most efficiently if the hydraulic fluid used has zero compressibility.
Usage examples of "hydraulic fluid".
Jake did a walk-around preflight check with his flashlight set for white light because in red light any red hydraulic fluid leaking from the plane would be almost invisible.
The gun had been hit by something, with all the damage it was hard to tell what, but the weapon, an HVM or maybe a plasma bolt, had dug a half-meter hole in the side of the massive shock absorber, spraying the area with hydraulic fluid.
Its armor buckled and battered, leaking hydraulic fluid and oil, the Beast rolled after them, crushing the remains of the mighty cannons under its armored treads, vaporizing the swift and blinding any who dared to glance its way.
Compressed nitrogen would be used to blow the gear down since hydraulic fluid was no longer available to do the job.
Even as he said it Greenburg remembered that the ground crew had been brought into the cargo deck further forward, that they hadn't seen the pool of hydraulic fluid that he and Lewis had had to step over earlier.
Instantly, Rochefort was surrounded by blinding sprays of hydraulic fluid.
Deep within the plumbing system of the 727's brakes, the air pressure released seconds before from the emergency bottle finally overrode the various valves and pistons and compressed the hydraulic fluid to the necessary pressure, instantly stopping the rotation of the main wheels.
So now the rotor blows-big fucking surprise- and the fragments cut into the wing, so that nonflammable hydraulic fluid is smoking.