Brake fluid is designed to operate under high temperatures therefore it contains additives that make it hydroscopic, this means its properties will become affected if it’s exposed to water. Brake fluid is not designed to last forever as moisture may affect the boiling point. For this reason brake fluid must be kept in a dry place and the rubber lid on the master cylinder must be sealed to prevent moisture and dirt from entering into this reservoir. Brake fluid is best kept for 12 months, and after that, throw it away as it may contain moisture.
Things to look for
Brake fluid, depending on its demand, may become discoloured. When this happens renew the brake fluid.. It is important to observe the brake fluid reservoir on a weekly basis as it may descend as the front disc callipers self adjust. It should only descend slightly, measured in millimetres at a time. If the reservoir descends completely in a month then it’s leaking. At this stage, don’t even drive the car to the garage. Brake fade is also a sign to change the brake fluid. Brake fade is when the pedal is still hard but there is no braking reaction
Is it expensive to repair?
Brake fluid is not expensive and if you decide to replace the brake fluid make sure your mechanic bleeds all the nipples and cleans the reservoir. If this is completely flushed, it may cost around $45.00 including time.
Temporary repair and long term replacement
Brake fluid may descend slightly in the reservoir as the disc callipers self adjust. At this stage it’s okay to top it up with new brake fluid to prevent the buoyant level indicator from switching the brake warning light on.
This article is found in the Virtual mechanic CD Rom
You can download it for the price of a latte, but you will learn not to buy a lemon
By Darren Gow-Brown, Melbourne Australia ©2009