The Automotive Maintenance and Repair Association (AMRA) recommends to its members that (1) Brake fluid be tested for contamination at OEM recommended brake system inspection intervals, and (2) that a Brake fluid replacement service be performed, for most vehicles, when testing shows copper content exceeds 200 ppm. The AMRA Technical Committee reached these conclusions after extensive study of industry data, including a review of SAE Papers, US Government reports (NHTSA and NIST) and independent laboratory studies, among other resources. The data showed that this increased presence of copper contamination predetermines the rapid growth of iron con-tamination and corrosion which has shown to impede future brake system performance.
What is a braking system?
How does a braking system work?
When the brake pedal is depressed, the pressure on the brake pedal moves a piston in the master cylinder, forcing the brake fluid from the master cylinder through the brake lines and flexible hoses to the calipers and wheel cylinders. The force applied to the brake pedal produces a proportional force on each of the pistons.
The calipers and wheel cylinders contain pistons, which are connected to a disc brake pad or brake shoe. Each output piston pushes the attached friction material against the surface of the rotor or wall of the brake drum, thus slowing down the rotation of the wheel. When pressure on the pedal is released, the pads and shoes return to their released positions. This action forces the brake fluid back through the flexible hose and tubing to the master cylinder.
What components are in the braking system?
Disc Brakes are comprised of a disc or rotor, a caliper assembly, disc brake pads and the wheel bearings and hardware necessary to mount the components on the vehicle. The caliper is connected to the master cylinder through tubes, hoses and valves that conduct brake fluid through the system.
Drum Brakes are comprised of a drum & backing plate, a hub or axle assembly, brake shoes , wheel cylinder, wheel bearings and hardware necessary to mount these components on the vehicle. The wheel cylinder is connected to the master cylinder through tubes, hoses and valves that conduct brake fluid through the system.
Brake fluid is a type of hydraulic fluid used in brake applications for automobiles and light trucks. It is used to transfer force under pressure from where it is created through hydraulic lines to the braking mechanism near the wheels. Braking applications produce a lot of heat so brake fluid must have a high boiling point to remain effective and must not freeze under operating conditions. Brake fluid is also designed to protect against corrosion of the system materials it contacts, however those corrosion inhibitors deplete over time. Excessive moisture is also an issue. MAP continues to seek additional information from brake fluid manufacturers and other technical experts to identify the point of vaporization that may seriously affect braking efficiency and safety.
Your driving type or vehicle usage may affect the maintenance intervals below. You should follow the manufacturer’s service schedule that best matches your vehicle’s operating conditions.
Proper Maintenance Helps Extend Vehicle Life!
Those recommendations may include:
- Change your engine oil every 3 months or 3,000 miles
- Check your tire inflation pressure monthly
- Rotate your tires every 6 months or 5,000 to 8,000 miles
- Change the engine air filter annually or when visibly restricted.
- Inspect Brake System every 12 months or 15,000 miles
This article was provided by Automotive Maintenance & Repair Association (AMRA) / Motorist Assurance Program (MAP)
AMRA/MAP believes that this information is accurate and reliable and does not endorse, approve or certify such information, nor does it guarantee the accuracy, completeness, efficacy, or timeliness; reliance on it should only be undertaken after a detailed review of the applicable OE publication(s).
AMRA/MAP is not responsible for, and expressly disclaims all liability for damages of any kind or consequences thereof, arising out of use, reference to, reliance on, or performance of such information.