Wheel about to lock- paul-ryan.info Plungerpump Dumpvalveopen Deboost pistonmoves up torelieve pressure

If the wheel decelerates too quickly, the unit's flywheel over-runs it, moves sideways and allows the dump valve to open, relieving brake pressure.

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How ABS works

One of the most unnerving things that can happen in motoring is that you brake and one or more of...