Question

For proper function hydraulics systems need a reservoir of which of the following?

A.) Compressible fluid
B.) Non-compressible fluid C.) Non-compressible air

Answer 1

A. Compressible fluid

Think of brake fluid on a vehicle, compressed as one applies the break= pressure to expand brake cylinders in the wheels which compress the pads on the wheel brake rotors.

Release brake and fluid relaxes back into the reservoir/accumulator.