Brake fluid flush interval

The major reason to bleed the brakes is that absorbed water lowers the boiling point and encourages corrosion.

How much humidity is in your locale will be the determining factor, we don't know your locale.

There are test strips and test probes so you can check the condition of your fluid.

www.amazon.com/Tester-Indicators-Diagnostic-Testing-BLACK1/dp/B07ZYFBTD9

www.amazon.com/Phoenix-Systems-8006-B-Double-Ended-Coolant/dp/B0753MZT7P

 

yep, no probs. that how you have to top off.

 

If there aren't any leaks, you should theoretically never have to top off the brake fluid. It's natural for the level to drop as the brake pads wear, and with pad replacement the level will go back up.

Can you clarify? Is that what they said, word-for-word. Considering your miles, and:

With a properly functioning brake system with no leaks (very likely the case), this is indicative of pads nearly worn out. Considering that and the miles, I suspect you need some new pads. Either check pad thickness yourself, or get a second opinion.

1. Toyota USA says nothing about changing brake fluid.
2. Toyota Canada says tri-yearly or 48K kms, whichever comes first. (as of maybe model year 2014)
3. Honda Canada says tri-yearly, period.

I go with #2

Have you ever had a full brake inspection, caliper's pulled off, pads inspected/cleaned, caliper pins lubed and so on? I would recommend tri-yearly or 30K miles.

Toyota USA sort-of recommends this, well they recommend something more extensive at that invterval, but don't really go into detail. This lack of guidance seems to "enable" dealerships and owners alike, to neglect regular brake maintenance.

 

Before you rush to top anything off, there are two things that affect the fluid level you see there:

1. as the pads wear over time, the level naturally drops. The fluid is occupying the equivalent volume that has worn off the pads. Replacing the pads with new thick ones would bump the level back up.

2. in operation, the system has a pump that takes fluid out of that reservoir and stores it in a pressurized accumulator. You don't see the right level in the reservoir unless you do a "zero down" operation first, which depressurizes the accumulator and lets the fluid back into the reservoir.

As kind of an "informal zero down", if you sneak up on the car first thing in the morning and peek under the hood without triggering the pump to run (as it does when you open the driver's door), then you'll probably see something close to the zeroed-down level. Then if you trigger the pump to run you'll see the level go down again.

Chances are that what you've described is just about right, considering all that and the miles on the pads.

Now, whenever you do decide it's time to replace pads, there are two schools of thought. One is to just shove the pistons back into the calipers, causing the old fluid to be pushed back up to the master cylinder. If you just do that and replace pads all around, you will probably find your zeroed-down fluid level to be right back where the factory filled it.

The other school of thought is to not push any of the aged fluid back up to the actuator. Instead, open the bleed screw at each caliper while you shove the piston back, and discard the fluid you shove out. When you're all done, then you top up with fresh fluid up front, and you've accomplished a kind of partial mini-flush (and also avoided pushing possible grot up into the actuator valves). Sort of a middle ground between never changing fluid and doing a full flush.

When checking with a test strip, the tradition seems to be (at least if hobbit and me doing it makes a tradition) to open one of the caliper bleed screws and collect a little fluid from there to dunk the test strip. The lines to the calipers are dead ends, so the fluid you collect from there has been pretty much stuck there forever, and experiencing the brunt of the heat from braking.

You can see pictures of results we obtained at 145,xxx and 110,xxx over here.

 

Ah, think I understand: new thickeness of all is roughly 10 (fronts are 10.0 mm and rears 9.5 mm). They're probably measuring 6 mm for all??

FWIW at 85K kms I've more'n likely got 6 mm, 7 mm at most, on the fronts. The rears are a long story, had to change pads early, my screw up.

 

If you topped off now, be alert for ending up overfilled when you get around to replacing pads.