Hey folks,

The Question:

Bought a brake fluid tester and want to test my brake fluid. When I open the top of the brake fluid compartment, there is some filter preventing me from submerging the tip of the brake fluid tester into the brake fluid. I put on some gloves and tried removing the filter, but I don't see a good way to do so.

Do I somehow need to remove that filter to do the fluid test? How do I do that?

Here is the tester I got:
Pics of the opened compartment top are at the bottom of this post

Background if needed

My Camry is roughly 30k miles (pretty darn low usage). Have always done basic maintenance at Toyota dealerships (once at a non-Toyota place just to see if I liked them better). Recently moved in the past year, so been using a new dealer. All of the dealerships I've gone to have seem to give random recommendations, and if I call them back and ask clarifying questions about the last service's recommendations, person on the phone will give different answers that the in-person conversation revealed.

In any case, most recent visit at the new dealership, I was told I needed to do a brake fluid flush. This was after the guy popped the hood and looked around for under 2-3 mins. I told him to hold off and just do the normal maintenance. The fluid doesn't look notable to me, but what do I know?

I do live in the Pacific Northwest, which apparently may make a difference in terms of expected moisture in the brake fluid.

 

Don't know as never removed one.

The link below may help.

My brake fluid reservoir has a plastic filter cap blocking the reservoir and I can’t get it off for the life of me… HELP!! : r/AskAMechanic

The tester appears to measure the electrical resistance of the fluid via the two probes. The more water in the fluid means greater electrical continuity.

You need only have the ends of the probes in the fluid. The fluid looks like it is touching the bottom of the screen.

The fluid looks great! The more moisture in the fluid the darker it gets. Brake fluid can become very dark to the point of being black.

Get a small bottle of the right kind of brake fluid and compare color. Place your probe in this fluid to get a reading for new fluid and compare with yours.

See link below.

Brake Fluid Color Chart: Find Out What Each Color Means

Most car owners never change it!

I would defer on changing the fluid myself as not needed based on your photos.

 

Thanks for the notes!

How do you evaluate your brake fluid?

One book I have says: appearance, consistency (i.e. does it feel gritty?), and smell (i.e. does it smell at all burnt?).

Another book I have says to just replace the fluid every 2 years.

The Camry documentation from purchase seems to just say pay attention to levels.

Thanks! I only searched on here and didn't find any good mentions. Funny enough, that thread basically has "all the options": (i) don't bother, just change your fluid every 2 years, (ii) its not removable, (iii) it IS removable (2-3 different ways proposed).

I think you're probably right but I don't have a great way to validate this. It could either be not enough fluid to measure, OR my fluid has no moisture.

Thinking you're right about this fluid being good.

I think my plan is going to be to (eventually) get some fluid, top it off to just under the max line, and then test the moisture content over the next few days/weeks once its more uniformly distributed. Looks like its pretty inexpensive (< $4.50 for a bottle).

Ha, funny enough even this source recommends just changing the fluid every 1-2 years.

Probably going to end up going with this in the end...after topping it off so I can more confidently measure the water content.

 

The consensus is to change the fluid every 2-3 years. If my car would not change it but this is me and I DIY.

Brake fluid absorbs water and oxidizes with exposure to air. With this it can start to turn acidic. One can test for pH acidity with pH test strips.

It also has anticorrosion additives. One can test for copper using test strips to check this condition. See link below:

When to Change Brake Fluid | Wagner Brake

There are test strips that claim they are better than copper tests.

BRAKE FLUID TEST STRIPS (50 Bottle) APS Color Key showing Good/Bad FREE SHIP | eBay

How is the braking action? Moisture in brake fluid may boil when hot and cause spongy braking. Brake fluid has a higher boiling point then water.

If the fluid gets too hot it can oxidize and may smell.

Never experienced gritty fluid. The cause would be containments from internal corrosion of steel brake lines and internal deterioration of the flexible lines that run to the brake piston on each brake.

Toyota appears not to list any interval for changing the brake fluid in their owner's manual. Their website seems to recommend the 2-3 year interval.

As you state everyone has their own opinion on your brake fluid. Keep in mind that profit can be a motivator.

I would be OK with the color of the fluid. You can run the tests yourself.

If you are concerned about car fluids the No 1 to keep an eye on is transmission fluid. Worn out fluid is the No 1 cause of transmission failure. Toyota has a color chart they use to compare to trans fluid with to determine condition. Or change it aall every say every 60-70K miles. Toyota may state it is lifetime fluid, but it is not. Trans fluid life is directly related its temperature. The hotter it gets, the shorter its life.