Brake Fluid Testing... Really? How?

By BRETT WINBERG

Does brake fluid last forever? The answer is NO! Many vehicles from motorcycles to large over the road trucks use specially designed brake fluid to assure proper stopping of the vehicle.

At least most of you or your customers probably understand why we change engine oil. The benefits go something like… removal of harmful acids, carbon and other contaminants that accelerate the wear on seals, bearings and various moving parts. Most might even understand that we change transmission fluid because the friction material gradually wears off the clutches, contaminating the fluid with a sludge that can wear seals and stick valves. And those who've read their owner's manual might even know that we change coolant because the corrosion inhibitors eventually lose their effectiveness with time and miles.

But why would your local repair facility recommend changing brake fluid? There are no combustion or friction materials to generate harmful byproducts, and it's a sealed system, so air, moisture or other contaminants cannot enter. So why do some manufacturers recommend changing brake fluid? Even more puzzling, why do others recommend against it?

Brake fluid, after all, is highly hydroscopic… it begins absorbing moisture almost the minute you open the can. Eventually, vapor pockets form in the hydraulic system, resulting in a spongy pedal and decreased braking efficiency. As if that wasn't enough, contaminated fluid also causes rapid corrosion and pitting of brake system components, particularly on antilock brake systems. Leave moisture-laden fluid in a modern ABS system for any length of time, and chances are real good your customer will have one hefty repair bill to deal with down the road.

Most of the corrosion in a brake system is caused by environmental contaminants like water, salt and oxygen. Wheel cylinders and calipers are out in the environment, and they are subjected to heat cycles that can distort the sealing surfaces. That's where contaminants are most likely to enter the brake system. This suggests that environmentally caused corrosion in these areas may have always existed, but in vehicles without ABS, brake fluid doesn't circulate through the system. Its movement is more like a control cable in its housing: There is back-and-forth motion of the fluid, but the same fluid touches the same parts of the system all the time. Any environmental contamination or corrosion will remain local. Over the years, better materials and coatings have been developed to survive such attacks, so it has become less of a problem on newer cars. But on cars with ABS, brake fluid circulates during ABS operation, so deposits caused by environmental corrosion can be carried by the fluid to other parts of the system.

FASCAR®, which stands for "Fluid Analysis by Stimulation of Contamination Alpha Reactions", and Wagner® Brake Company offer a simple visual test to determine the condition of your brake fluid. To test, immerse the new “Test Strip” into vehicle’s brake fluid for 10 seconds and within 30 -120 seconds the reaction zone will change colors depending on the condition of the brake fluid… nice job!

Use the color scale to compare the reaction zone color to determine the brake fluid rating.

The strip measures the "virtual age" of the brake fluid. Many factors effect the condition of brake fluid such as:

The "virtual age" of the brake fluid is determined by these factors and technology can measure their effects on brake fluid. As an example, a vehicle may have only 12,000 miles, but due to the thermal effects on the brake fluid it may have a "virtual age" to that of brake fluid with 30,000 or more miles. This condition has been demonstrated on high performance vehicles that are repeatedly subjected to high amounts of heat… the test strip can measure these effects, as well as others, in a simple visual test.

The only brake fluid recommendations that are made worldwide are TIME and MILEAGE based. Over 70% of the world’s auto manufacturers recommend brake fluid flush service based on a TIME/MILEAGE criteria or "AS NEEDED". There was no technology available that could track TIME/MILEAGE or the "AS NEEDED" condition of brake fluid. Hence, the need for this technology. This technology is the only brake fluid test in the world, which makes a brake fluid flush recommendation based on TIME/MILEAGE criteria. *To conform to OEM recommended flush intervals Euro/Asian vehicles have a higher standard.

What Happens When Brake Fluid’s Ability to Protect is Impaired?
If you wait until your brake fluid fails a moisture test, it may already be too late! After brake fluid corrosion inhibitors are severely depleted, corrosion of the internal components begins. Corrosion can pit the metal bores of the master cylinder, slave cylinders and ABS components. This means that pistons cannot move freely, seals can be damaged and cylinders can develop internal or external leaks. A thorough brake fluid flush-and-fill is cheap insurance.

Test Strip Features:

If you would like more information on how to obtain Wagner ® Test Strips, send and email here.

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