Rick's Free Auto Repair Advice

Is a brake fluid flush necessary?

Should you get a brake fluid flush?

Probably, but it depends on why the shop is recommending a brake fluid flush. Brake fluid is hygroscopic, which means it likes to absorb water. But a brake system is considered a sealed system, so how does water get in the fluid? Two ways; first, if you remove the cap to add fluid, ambient air moisture gets sucked into the fluid. Second, as the caliper and wheel pistons move in and out of their bores, moisture can get pulled into the system from the microscopic pores in the pistons.

Shop says brake fluid looks dark

Nobody can determine the condition of your brake fluid with a visual inspection. There are two tests to determine if the fluid needs to be changed. The first is a test strip that checks the level of copper in the fluid. As moisture accumulates in brake fluid, the water corrodes the inside of the steel brake lines. Steel brake lines are formed from rolled steel that’s brazed along its length. Water degrades the braze and leeches copper into the brake fluid. So high copper levels are an indication that it’s time to get a brake fluid flush.

The second test is done with a moisture meter. brake fluid flush, should I get a brake fluid flushDip a tester into the fluid and it tells you when the moisture level exceeds a certain level.

Is brake fluid flushing a scam?

It depends. Some car makers recommend a brake fluid flush on a set schedule like every 2-years or 24,000 miles. They base that recommendation on rough estimates of how many times you might apply your brakes during that period, how hot the brake fluid might get, and based on those projections, they estimate how long the fluid’s corrosion inhibitors may last. Does that mean your fluid is bad? Maybe. Maybe not.

On the other hand, most American car makers don’t list ANY brake fluid changes as required maintenance—ever. So shops often step into the void and recommend them anyway. It’s a money maker for them. Brake fluid flushing takes less than an hour to perform and costs about $4 in fluid. The rest is all profit.

How can you avoid getting scammed on a brake fluid flush?

Buy a package of brake fluid test strips. Open the brake fluid

brake fluid flush, should I change brake fluid

Buy a package of brake fluid test strips and test your brake fluid so you don’t get scammed.

reservoir and dip the strip into the fluid. Wait the recommended amount of time for the strip to change color. Then compare the color to the chart on the package. If the chart shows the fluid is old, change it. If not, don’t.


Where’s the best place to get a brake fluid flush?

Avoid oil change shops. PLEASE! If you read the news, you already know that the chain operated shops are known for scamming customers. How do they scam you on a brake fluid flush? Simple. They use a turkey baster and suck the dark fluid out of the brake fluid reservoir. Then they add clean looking fluid. They never actually bleed the old fluid out of the system.

So find a reputable independent repair shop. Read this post first before you start looking for a good mechanic.


How to find a good mechanic

©, 2016 Rick Muscoplat



Posted on by Rick Muscoplat


Custom Wordpress Website created by Wizzy Wig Web Design, Minneapolis MN