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Brake Fluid Service (flush)

The fluid in your car’s brake system deteriorates over time and should be replaced at manufacturer recommended intervals or sooner if the fluid fails testing. The service is inexpensive on most vehicles and can prevent damage to expensive brake components.


The biggest issue with brake fluid is that it is hygroscopic which means that it naturally absorbs moisture from the air. The higher the humidity the quicker this occurs. (This is why that once a container of brake fluid is opened the fluid should be used relatively soon before it becomes moisture contaminated.) Professional shops have test equipment that can measure the amount of water in your brake fluid.


The solution is replacing all of the fluid in your brake system at the recommended interval which is 2 to 3 years for most vehicles (see your owner’s manual). The number of miles you drive is not a factor.

Results of neglect

The following are the 3 most common problems that can occur if the brake fluid maintenance is overlooked.

1: Decreased braking with higher temperatures

Water (moisture) boils at a lower temperature than brake fluid so as the moisture level increases the boiling point of the fluid decreases. Under demanding conditions such as towing, driving in mountainous areas or when constant repeated braking is required boiling fluid can cause serious brake failure. If you watch car racing sooner or later, you will see crashes caused by this.

2: Corrosion

Water is also heavier than brake fluid so the fluid will collect in the low points in the brake system. The resulting rust and corrosion can damage lines, seals, calipers, ABS parts and other components of the system.

3: Sludge

Water in the fluid will also cause a buildup of sludge over time and prevent the proper flow of fluid through parts of the brake system where passageways are often very small. This is especially true of antilock brake parts which are normally the most expensive parts in a brake system.


The difference in the cost of regular fluid services and major brake repairs can run into the thousands of dollars when parts designed to last the life of the car have to be replaced due to contaminated fluid issues.


On many vehicles the tools and equipment required to properly service the brake fluid are fairly common while on others expensive specialized high-tech equipment may be needed. Still, the cost is not great in most cases. Most shops can provide a price for you quickly. Also, check our current auto repair specials to see if we can save you some money.
