Hydraulic pumps are very simple and have many uses. Its basic design is a piston in a cylinder that exerts pressure on an incompressible liquid (usually oil), and the force is transmitted to another piston that will do something useful for you. The force is usually multiplied in the process, therefore the second piston can achieve much more than the first. To add force multiplication, the relative size of the pistons is increased.

The oil must be free of air bubbles because if one piston is used when bubbles are present, much of the force is wasted compressing those bubbles instead of driving the second piston, which is hardly an efficient way of doing things. Most pump failures are due to oil contamination of one kind or another. Oil reservoirs should be made of stainless steel or aluminum to prevent corrosion and reduce the chance of oil contamination.

The tubing that contains the oil can come in all kinds of lengths and shapes in a hydraulic pump, which is very useful because it can be used in almost any system design. The pipes can also be branched so that the master piston drives two or more slaves.

You may not know this, but you probably have a hydraulic pump. Cars use them for the braking system. When you press the brake pedal, you push two master cylinder pistons, each of which drives two slave pistons (there’s one on each wheel). These, in turn, press the brake pads against the brake rotor to stop your vehicle. The reason two cylinders each drive a pair of cylinders instead of one cylinder driving four is in case there is a problem with a master cylinder; in this case if you only have one you cannot stop the car because all your brake pads will then be ineffective.

Some hydraulic pumps are manual and others are powered by electricity, compressed air, or gasoline. Manual hydraulic pumps are great because they have portability because they don’t need an additional power source. They are perfect for occasional tasks, but lack the power and speed of motorized pumps. They are also labor intensive.

Electric and pneumatic pumps are good when the required power source is available. They will do more in less time than a manual hydraulic pump, but the downside is their cost and the fact that they must be powered by air or electricity, so the supply must be close at hand.

Gasoline pumps are good for situations where a hand pump is not powerful enough and where the limitations of a pneumatic or electric pump do not allow use in remote locations.

Hydraulic pumps have all kinds of uses, but if you find that you need to buy one yourself, be sure to do your research and get the right one.