Brake fluid is hygroscopic (bluntly, it means it absorbs water). As the fluid absorbs moisture in the air we breathe, mainly through rubber brake hoses and seals, it lowers the boiling point of the fluid.
To put it simply, using the brakes creates tremendous heat and if the brake fluid happens to boil your pedal will more than likely drop to the floor. Every service we send an electronic pulse through the fluid to test it, advising you if it is time to have the brake fluid flushed and changed.
The cost of flushing and replacing brake fluid may be quite minimal on many vehicles, but the cost of not doing so can run into the hundreds or even thousands of dollars. Without maintenance, you may end up with rusted brake lines or brake calipers, and other problems with brake parts. This is why it’s vital to inspect and test the brake fluid for moisture content every two years. If you live somewhere with high humidity, you could potentially push this timeframe out to 3 or 4 years, but obviously the more frequently, the better.
Another important note is that winter weather can bring with it salt and other contaminants, which can get into the brake fluid. So vehicle owners in these colder areas (especially where it snows) should pay particular attention to checking their brake fluid.
Ultimately, brake fluid is as critical to stopping your car as engine oil is to keeping your car running. It’s of paramount importance that it’s checked on regular basis by a knowledgeable car expert, or preferably a qualified mechanic.