The liquid that creates the pressure is the factor of which valves are working and handle the system. Using fluids is better and usable for equipment motion than using dry techniques. The fluid will not create the identical friction on systems, also it does not need a lot of pieces and it has a softer and more accurate movements.
If a hydraulic gauge is not running properly, then the hydraulics might fail. The hydraulics can energize brakes, a clutch, a loading container, or some other touching equipment, thus there might be severe damage waiting to take place if they stop working.