A hydraulic handbrake is a key piece of equipment for any motorsport enthusiast. It's common to see a hydraulic handbrake on a drift car to allow the driver to lock up the rear wheels temporarily to shift the weight / balance of the car. On a drift car its used to initiate a drift, alongside throttle input to maintain the drift. Other techniques such as clutch kicking or the scandinavean flick are also used to initiate a drifting.Hyrdaulic handbrakes are also known as hydro, hydro brake, e-brake, or wand depending on which part of the world you are in.Traditional handbrakes are made up of a cable which connects to a Y somewhere towards the rear of the vehicle which is then connected to brake drums. Whilst the cable system can be used, over time the cable can stretch requiring adjustment, or in worst case scenario snap completely. A traditional cable operated handbrake doesn't have the stopping power a hydraulic handbrake does. AHydraulic handbrakes are connected inline into the hydraulic braking system of the car. When you pull on the handbrake, this level action pushes a master cyclinder and high-pressure brake fluid is pushed into the rear brake calipers which in turn operates the rear brakes. For this reason it's common to see a hydraulic handbrake on race cars that have disk brakes all round. When used in conjunction with a good brake pad compound and quality brake disks you can lock up the rear wheels on just about any car.In some instances hydraulic handbrakes are paired with a second set of brake calipers, this would involve running separate brake lines and a brake fluid reservoir. Whilst more expensive, it means you have dedicated brake calipers for the hydraulic handbrake.It's worth noting that if you're building a car with disk brakes all round it is illegal to have a non-working handbrake fitted - i.e. one without two main operating brake calipers.Hydraulic handbrakes are also found on Rally cars and Drag Cars. For a RWD Drag cars it can be used to lock the front wheels to initiate a burnout or used for staging at the Drag Tree.For Rally cars its used for tight hairpins, you only have to watch a Ken Block video to see how often a hydraulic handbrake is used to get the car to change direction suddenly.