Basic Hydraulics Practice Test 2026 - Free Hydraulics Practice Questions and Study Guide

In a hydraulic system, the fluid carries energy in the form of pressure as it is pushed from the pump. As it travels through pipes, hoses, fittings, valves, and actuators, it encounters resistance at every step. That resistance—friction, restrictions, and losses in components—takes energy out of the moving fluid, converting some of it to heat and leaving less pressure downstream. Because these losses accumulate along the path, the pressure drops progressively as the oil moves through the system. The flow rate tends to stay relatively steady (set by the pump or system controls), so the key change you notice along the route is a decreasing pressure.