Static brake test
The static brake test is just a matter of pressing the brake pedal when you get into the car. There should be resistance from the pedal; if there isn't and the pedal feels soft or easily pushes to the floor you have probably got a fluid leak and should not drive the car.
Rolling brake test
Complete your 'rolling brake test' by pressing the brake pedal gently as soon as possible after moving off and while driving slowly. This will reassure you that your brakes are OK before you need them. Note: this is not an emergency stop! Simply 'feel' the brakes at five or ten kph.
Brake Fluid Should Be Tested
Symptoms of impending brake failure
Brakes operate on a hydraulic system; for the system to work effectively there must be fluid in the hydraulic pipes. If the fluid starts to leak from the system the brake pedal will feel 'softer' and will often travel further when pressed. If your brake pedal feels soft or 'spongy' stop immediately and get a breakdown mechanic to check the car.
When the brake pedal feels soft, you might be able to build up brake pressure by repeatedly pumping it, however, this is only an 'emergency' measure to stop the car once - it is not a 'get you home' solution. Driving with a 'soft' brake pedal is extremely dangerous because your brakes could fail at any moment, even if they don't fail they will be inefficient, possibly leading to an accident.
If your brake pedal feels hard and the brakes are not working or are inefficient, something might have broken in the braking system - BUT... It could just be that something is jammed under the brake pedal. This is why you should keep the floor area of your vehicle free of litter and other stuff that could slide under the pedals.
Total brake failure
If you need to stop 'now!' use a hand operated parking brake (handbrake) in an on-off pumping motion, keep the release button pressed as you do this.
If there's time, change to second gear and ease the clutch pedal up gently (the engine compression will make the clutch feel like a brake) then use the parking brake to stop. In an automatic, shift to 'low' - if there is a manual option on your auto, change down one gear at a time.
If you have a pedal operated parking brake you need to operate the brake release handle at the same time to avoid locking the rear wheels - parking brakes only operate on the rear wheels (with very rare exceptions).
Using the parking brake or dropping a gear at high speed could be dangerous and lead to a loss of control - lose as much speed as you can naturally before doing either of these things.
If you use the parking brake pull it gradually - a sudden tug on the brake or push on the parking brake pedal could lock the wheels and lead to loss of control. Locking the wheels might slow the car quickly in a straight line but the resultant skid could make the vehicle uncontrollable, possibly skidding off the road. If you have an electronic parking brake only use it in a last resort emergency - these brakes tend to operate on an 'on/off' basis and will probably lock your wheels solid.