The Three Self-Tests

Three checks that catch brake problems before the road does:

1. The 20-second pedal test. Engine on, press the pedal hard and hold for 20 seconds. Pedal sits very low → wear (service due). Pedal keeps sinking slowly even at the bottom → a hydraulic leak — a serious hazard; do not drive until fixed. Pedal feels springy/spongy → air in the system (workshop bleeding job).
2. The servo test. Pump the pedal several times with the engine off (exhausting the vacuum), then hold the pedal down and start the engine. If the pedal sinks as the engine starts, the servo works. No sink = no assist = double the pedal effort in an emergency.
3. The pull test. Under gentle braking on a straight, empty road, a car that pulls to one side has uneven braking across the axle (workshop). Distinguish from the steering pull of misalignment (Lesson 5.4) by whether it appears only under braking.

One habit worth adopting locally: after washing the car or fording water, brakes can be wet and weak — a few firm, controlled applications dry them out. Relevant after every flooded-road season.