Hydraulics Academy

How hydraulics works Learn it by playing with it.

Learn how hydraulics works by playing with it. Interactive animations in real units, from the first push of a jack to load-sensing pumps and steering gear, and every lesson lets you break the machine and see the symptom.

interactive lessons, from first principles to whole machines: 20
reading depths on every lesson: Simple, Engineer, Deep dive: 3
"Break it" faults to try, each with the symptom you'd see on site: 19
cost. A free account opens every lesson; nothing to download: 0

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Move the lever. Then break something.

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03Pump, relief, control valve, cylinder

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Level 1

Foundations For anyone: what hydraulics does and why it works.

01 Pascal's law and the hydraulic jack Push a jack handle, change both piston sizes, and watch force and distance trade. Break it: a leaking check valve lets the load sink between strokes. Open to everyone 02 Pressure and flow A pump, a needle valve and a lifting cylinder, with a gauge either side of the valve. Break it: a partly blocked line (high pump pressure, hot fitting) and a relief set too low. Free account 03 Your first hydraulic circuit Lever, load, pump flow and relief setting, with a live gauge and the heat being made. Break it: a worn piston seal (the load drifts) and a worn pump (the lift slows). Open to everyone 04 Reading hydraulic symbols Twelve ISO 1219 symbols; pick one and the real part beside it works. Then test yourself. Free account 05 Oil, heat and viscosity Oil temperature, ISO VG grade and viscosity index, with a live chart and a valve clearance leaking. Break it: a failed cooler in summer heat, and a top-up with the wrong grade. Free account

Level 2

Components Pumps, valves, cylinders, motors and the parts that keep oil clean.

06 Gear pumps Spin the gears, change speed, displacement and pressure, and watch flow and efficiency. Break it: worn side plates (flow falls as pressure rises) and a clogged suction strainer. Free account 07 Axial piston pumps Tilt the swashplate, change speed and pressure, and follow each piston round the valve plate. Break it: worn valve plate and slippers (case drain flow climbs) and a blocked case drain. Free account 08 Relief valves Turn the adjuster, raise the load and flow, and switch between direct-acting and pilot-operated valves. Break it: a weak spring, dirt on the seat, and a blocked pilot orifice. Free account 09 Directional control valves Move the lever, change the centre type, and watch the spool and the ISO symbol move together. Break it: a worn spool that lets the load creep (worse when hot) and a sticking spool. Free account 10 Check and pilot-operated check valves Raise, hold and lower a load through a pilot-operated check, and change the pilot ratio. Break it: dirt under the seat (the load drifts) and a blocked pilot line (it won't come down). Free account 11 Counterbalance valves Lower a crane boom with and without the valve, then change the setting and the pilot ratio. Break it: a weak spring (the boom drops), dirt holding it open (it drifts) and a seized valve (it won't lower). Free account 12 Hydraulic cylinders Bore, rod, pressure, flow and stroke, with extend, retract and regeneration. Break it: a bypassing piston seal, a scored rod leaking at the gland, and a bent rod. Free account 13 Hydraulic motors and winches Haul, stop and pay out a load; change motor size and drum diameter and watch pull and speed. Break it: a worn motor (slow, then the load slips back) and a brake that drags. Free account 14 Accumulators Precharge, minimum and maximum pressure and size, with the pressure–volume curve drawn live. Break it: lost precharge, precharge set too high, and a burst bladder. Free account 15 Dirt, clearances and filters Pick a filter, set a valve clearance, read the live ISO 4406 code, and watch particles pass, scrape or jam. Break it: a clogged element opening its bypass, and a missing breather cap letting dust in. Free account

Level 3

Systems and faults Whole machines, energy and the faults engineers chase on site.

16 Pressure-compensated and load-sensing pumps Switch between three pump systems doing the same job and compare useful and wasted power. Break it: a blocked load-sense line (the machine goes weak) and a margin set too low or too high. Free account 17 Hydraulic heat Pump flow, load pressure, relief setting, air temperature and tank size, with oil temperature over time. Break it: a leaking relief valve, cooler fins blocked with dust, and a low oil level. Free account 18 Cavitation and aeration Suction bore and length, oil temperature, tank level and pump speed, with a live inlet vacuum gauge. Break it: a clogged suction strainer, an air leak at a suction fitting, and a return line splashing above the oil. Free account 19 Ship steering gear Steer from the helm, change ship speed and gear type, and run the SOLAS timing test against the clock. Break it: a worn pump, air in the oil, a leaking locking valve and a failed ram seal. Free account 20 A crane circuit, end to end Slew, luff and hoist at once, change the hook load and pump flow, and watch one pump share its oil. Break it: a leaking counterbalance valve, a worn hoist motor, a slipping winch brake and a clogged return filter. Free account