Copper contaminated brake fluid?

Recently had front brakes done on "05 Buick Lesabre. Garage said a test strip showed copper contamination in brake fluid, so I agreed to a fluid flush. 2 monthes later, oil change at same garage, they said brake fluid was contaminated with copper, wanted to flush it. Is this a real problem, or are they blowing smoke up my whatiz? What is the potential downside? Thanks to all who reply.

Is this a quick oil change place?

When tests of brake fluid show a high level of copper, this indicates that the corrosion inhibitors in the fluid are depleted. It is very unlikely that the corrosion inhbitors would be depleted within 2 months. Two years, possibly. Two months–no.

Frankly, I am skeptical of their claims.

Do you have copper or brass lines or fittings? If not, there is no way copper can get into the fluid - it isn’t there.

Why would the shop pick copper to be the contaminate and not just water?

“Test Strip”??? Copper??? Sounds like complete BS.

The brake caliper to hose uses copper sealing washers. A brake fluid flush is good but it sounds like their pitch is full of pitch.

As I said previously, it is virtually impossible for copper levels to reach a high level in brake fluid within 2 months, but regarding the topic of brake fluid and copper:

“The Automotive Maintenance and Repair Association (AMRA) has
issued a Uniform Maintenance Service Recommendation for
changing brake fluid when its copper content reaches 200 ppm.
This recommendation was issued by the AMRA in April 2004, and
is based on extensive testing determining copper content to be a
predictor of brake system corrosion. As the corrosion inhibitors in
brake fluid deplete over time, copper components in the brake
system are among the first to corrode, with copper levels rising in
the brake fluid as a result. Copper corrosion is closely followed by
corrosion of iron based components, indicated when copper levels
in the 150-200 ppm are reached. To provide maximum brake
component life, corrosion in the brake system must be minimized
by periodic brake fluid changes. Such fluid changes maintain
proper levels of corrosion inhibitors in the fluid and also minimize
water content.”

This is who the AMRA is:

Dave Baier
Monro Muffler and Brake

Vice Chairman
Richard Schossler
Goodyear Tire & Rubber Company

Secretary/ Treasurer
Stuart Manning
Just Brakes

Immediate Past Chair (Ex-Officio)
Jack Fischbein
Jiffy Lube International
Chuck Abbott

Denny Bowen
Hunter Engineering Company

Mark Christiaanse
Tenneco Automotive

Joe Henmueller
Midas International

Ricky Jackson
Jiffy Lube International

Alex Kolosiwsky

Jack MacDonald
Pep Boys

Len Vogt

I don’t see one car manufacturer in the group.

…and some car manufacturers still don’t list brake fluid changes anywhere in their maintenance schedule, despite the fact that brake fluid is hygroscopic and does deteriorate over time. As we all know, car manufacturers like to make their products appear to be as maintenance-free as possible, and are beginning to delete references to transmission fluid changes in addition to the fact that they may have never listed brake fluid changes in their maintenance schedule.

Just because you and I would not necesarily want to patronize any of the firms that you listed above, does not preclude that it is just good practice to do a brake fluid change every 3 years or so. And, if the presence of copper in the fluid is a valid early warning of the need to change brake fluid, that might be a good thing to know.

However, as I said previously, if the OP had his brake fluid changed 2 months ago, then someone is just trying to blow smoke up his butt with the recommendation to change the fluid again.

I suspect the “Test Strip” ALWAYS reveals the need for a brake fluid flush…

I got the fancy treatment, the guy shoved an electronic gizmo into my brake fluid, came out with a red LED flashing, told me I needed a flush. I told him I’d do it (I did), he obviously didn’t like that answer. I open my hood a day later, there’s the brake reservoir cap sitting on the inner fender! I got the last laugh - he left the gizmo there, too.

I also am worried about a group that makes money selling (often unneeded) maintenance coming up with these dire predictions. I would believe it if it came from a brake manufacturers association. Not them.

I found this thread to be quite informative.

Who would have known the quick-lube class of repair places would have come up with their own official-looking maintenance procedures to sway the customers with. How low will they go?


Do you still have it? It would have been interesting to submerge it into a fresh bottle of brake fluid and see what it does…

I replace my brake fluid every 3 years, brake fluid will absorb moisture. I say it is a must if you have ABS.

Yes, I do - I’ll give it a try, first brake fluid, then water…we’ll see.

They are not mentioning water contamination, just copper. I looked at a couple of websites which turned out to be put up by the people who make the test strips. Lots of testimonials from garages who were able to sell this service. Haven’t seen a real description of what happens to a system with copper in it. The garage is Tires Plus, they do a lot of different types of repairs.

I saw a customer get the same hard sell at a local garage today. Google “fascar brake fluid test” and you’ll get a ton of information, basically from the test manufacturer saying how much better the test is than testing for water in the brake fluid. It also heavily promotes the test for garages as a way to make a ton of money, saying that about 1/2 the cars you test will fail the test (and need an expensive brake flush).

Anyway, in reference to the OP, somewhere in there they say that if the you fail the test after a flush, it’s because the garage didn’t use sophisticated flushing tools, and that the old “pump the pedal until the fluid is clear” method would NOT be adequate to flush the copper out. They say if you paid less than $75 for the flush, they didn’t do an adequate job. They have a free offer of test strips for garages, but insist the garage has to own the right tools (which they manufacture and sell) to get the offer.

I would buy some strips myself, but the smallest tube contains 100, and costs about $50, which is more money than I have curiosity. They say they are working with AutoZone to have a DIY alternative (presumably to sell smaller numbers), but nothing on the AutoZone web site indicated it has happened.

I was hoping someone here knew more. Is this controversial? Their science seems sound, but the hard sell is unsettling. It seems unlikely that half the cars on the road today need their brake fluid flushed right now.

It’s not a big deal for me, since I only own Honda’s, and Honda is one of the manufacturers who has always recommended fluid flush. I usually have it done when the front pads are replaced, but that is quite a bit longer than the 3 years Honda recommends.

I find it really funny that some of the people on this board give automotive advice when they don’t have any idea what they’re talking about. It’s kinda scary!

Read this and you just might get educated! But I doubt it!


I know. I said that front struts don’t swivel. I know that they do. I can’t tell front from rear some days.

I’m not sure what point your comment is trying to make.

To me, this thread isn’t disputing the need to replace contaminated brake fluid. Rather it points out the brake-flush-profit-generator schemes employed by some of the national car repair chains.