Whether the road is steaming hot or icy cold, your brakes are designed to handle the condition and pull two tons of steel from 105 km/hr to a complete stop. It's a reliable system designed for such stress, but you also have to assume the system becomes damaged from such stress over time. The solution engineers have determined to be the best compromise is to design a brake system with redundancy for emergencies and is easily accessible for repairs or required maintenance.
Brake service requires more than just installing new brake pads. As the pads wear down, the fluid level lowers to fill the gap. The simple solution is to refill, or “top off,” the fluid level to maintain the proper hydraulic pressure the brakes require to function efficiently. When it comes time to replace the pads, the backpressure will force the excess brake fluid out of the reservoir and cause a mess in your engine compartment. A better approach is to drain the brake fluid first and replace it afterward, which also means you have to bleed the lines by allowing fluid through to fill any air which might block the otherwise contained system.
The main reason for exchanging brake fluid was included with the description of changing brake pads, but there are further considerations involved. The first being that the technician needs to inspect the brake fluid. Debris or condensation polluting the fluid indicates a different problem elsewhere in the system. The second reason being that brakes generate a lot of heat during normal use, and that heat causes a molecular breakdown of the hydraulic oil used as brake fluid to run the system efficiently.
It doesn't take an engineer who designs brake systems to understand why you can't drive without brakes. With that said, brakes have enough redundancies to prevent an utter failure. First, there will be an obnoxious squeal as a brake pad exposes a wire to alert the driver of the need for brake pad replacement. If that sound is ignored, it will soon be replaced with the sound of metal housing parts grinding directly against the steel rotor. For your own and your family's safety, come by Sherwood Ford in Sherwood Park, AB for brake service or other maintenance your car needs before it becomes a worse problem with more expensive repair needs.