how does a hydraulic jack works?

Question

I need to know hoe does a hydraulic jack work in detail, including the hydraulic fluid, how does it react to the pressure applied

Answer 1

A manual hydraulic jack has a large area piston and a small area piston with a check valve in between and a fluid reservoir with a check valve to the small piston. A handle or foot pedal is attached to the small area piston so that it can be pushed down with moderate force. This pushes a small amount of fluid past the main check valve under pressure. When the small piston is returned, the main check valve prevents fluid from returning and the reservoir check valve admits fluid under the small piston.
Repeated pumping of the small piston gradually applies more and more pressure, but since the psi is applied to the small area of the piston, it is only moderately difficult to do this. When the same pressure is applied to the large piston, it can lift a large weight because liquids do not compress, but each pump only raises the large piston a small amount because only a small amount of fluid is transferred.
Operation of the jack is enhanced by have a lever of some length as the handle so the small piston may be moving 1/2" while the end of the handle is moving 4".
When the load must be lowered or the force relieved, there is a bypass valve that can be opened and all the fluid under the big cylinder drains back to the reservoir.
In a mechanical jack with a motor, a rather small but high pressure pump supplies the forces instead of the small piston and the large cylinder is usually much bigger - as in an elevator, car lift, or power tool.
Any fluid can theoretically be used in a hydraulic system, but the specific fluid used is oil based and provides lubrication while not damaging the system. Water would corrode most cylinders and many other fluids might break down under the force or leak and be flamable.