Brake Fluid testing - moisture & copper

[DIY4quality]

Typically, testing for brake fluid contamination is done at the master cylinder reservoir for obvious reasons. For moisture, it's probably the best place since air bubbles rise and the reservoir is located at the high point of the brake system. So you're getting a sample of the worst moisture condition, a good test.

And copper test strips are also dipped in the reservoir. But I'm thinking a better place would be at the caliper as the low point of the system where particle contamination is more likely to accumulate. Testing at the reservoir, while more convenient, is understating any copper contamination that may be much worse at the components lower in the system.

So I'm very curious to ask if anyone has actually compared a copper test strip at their reservoir with a second test strip at their caliper, perhaps when bleeding the brakes and some expelled fluid was handy?

 

[bdcardinal]

I haven't tried it, but I should have a brake flush coming up on my mom's 2014 Fusion which has never had the fluid done.

 

[MasterSolenoid]

I change my Brake Fluid every two years using one quart of fluid each time.
That way I don't need to worry about any testing.
Old Fluid is usually a straw color.

 

[KGMtech]

Test strips are not needed if you replace the fluid every 2-3 years. Just like brake fluid, the test strips are sensitive to exposure to air and become useless, for a DIY person the quantity you have to buy is wasted by the time less than 30% of your original purchase is used up.

I will say, tongue in cheek, that OP has a brake fluid fetish.

 

[ET16]

Do the test strips work with all types of coolant? I thought I heard that were only good for conventional, green coolant.

 

[DIY4quality]

Originally Posted by KGMtech
... I will say, tongue in cheek, that OP has a brake fluid fetish.

Yes indeed, that's why I'm here and more to come!

 

[DIY4quality]

Originally Posted by ET16
Do the test strips work with all types of coolant? I thought I heard that were only good for conventional, green coolant.


That's true for the coolant strips. My question is in regard to the brake fluid strips.

Note that some strips have the brake fluid test pad on one side of the strip, and the coolant test pads on the other side of the strip.