According to Scotty Kilmer (at least on his toyota), there is no need to change the brake fluid for at least a decade:
In fact, he uses a brake fluid tester (1:35min) which I think tests the “water content” in the fluid to see if it has gone bad. How accurate are these testers?
you could probably go ten years without changing your oil too. but your engine would be shot at 9/12 yrs.
I am unaware of any Toyota which uses DOT 5 brake fluid. If there is one that I don’t know about, then I can see going a long time between changes because unlike normal brake fluid, DOT 5 does not absorb moisture and therefore does not need to be changed nearly as often provided the system stays sealed (otherwise water will collect at the lowest point - the caliper - and require some doin’, as they say, to drain off).
DOT 5 is not, however, compatible with systems using DOT 3, 4, and 5.1. Any brake system using those fluids should have the fluids replaced every few years.
Wow, wish I’d known about this tester earlier. Here it is sold on amazon:
Many reviewers say they tested a range of old and new fluids and found the results to be accurate. And one reviewer said he even tested some new fluid and found it was contaminated right out of the bottle.
It indicates percent water content in increments of one percent, from zero to four percent. I’m guessing it measures conductivity between the prongs, with conductivity increasing as water content increases. It’s a simple measurement that can be done accurately with simple electronics, so I would trust the tester after trying it on a range of brake fluids and assuring myself that it seemed to be functioning properly.
A few reviewers complained that their tester didn’t seem to work properly, which is probably par for the course on an inexpensive electonic device from Taiwan.
And I think there is no need to go to the dentist every couple of years, because I don’t get cavities. This whole cleaning and checkup scam that dentists have been using to fleece us out of our money is outrageous.
Do the test strips work?
There is more to it than water content…The fluid just gets dirty…Wear particles from all the moving parts…A brake fluid change is cheap insurance…
The test strips only test the copper content of the fluid, and recommend that the fluid should be changed when the copper level reaches 100 ppm. The strips do not indicate moisture content.
But, you say, How does copper get into brake fluid? And why is it bad? Read this:
Most Americans don’t understand nor believe the need to change brake fluid every 3 years or so. And we pay for that in corroded caliper pistons. Europeans change their fluid regularly because the cars won’t pass the rigorous inspections of the TUV (Germany) or MOT (Britain).
Scotty is wrong.
Here’s another good article about water and copper in brake fluid:
My boss just had a brake line give out while he was driving a company vehicle. I think I’ll err on the side of caution and continue to change my brake fluid every couple years.
I don’t put a lot of faith into Scotty Kilmer recommendations. He’s the same guy who changed the timing belt only on a high miles old car while ignoring the rest of the kit; and on an interference fit engine to boot.
He also recommended drilling a hole in the A/C evaporator case to add a manual thermostat and bypass the car’s existing electrical controls.
I’m happy for Mr. Kilmer. I’ll stick to the practice of flushing the system with fresh fluid every 5 years.
My goal is to keep the car safe rather than go as long as I can with the same fluid.
I wonder how long Mr. Kilmer goes between oil changes, and spark plug changes, and tranny servicing.
Hmmm. Test kit for $20+, quart of brake fluid for $8? Three unnecessary fluid changes to even break even? Like oil analysis, nothing wrong with it but the analysis costs more than the oil changes. Great for the testing folks, questionable for the consumer. Who uses DOT 4 anyway though?
Me. I run DOT 4 in my Acura because I occasionally am at a race track with it that lets you drive the track in your own car, and I don’t want the fluid boiling so fast if I impulsively decide to be a dork and run it in a 4 door family car. My fun car gets 5.1 for the same reasons (I drive it a lot harder out there).
Toyota never used dot 5 unless the Lexus lfh did.
That’s interesting, OK4450. The guy sounds like a certifiable loony.
I am fine with changing brake fluid when new brakes are installed,currently a 6 year 85k cycle, have not even considered any other plan. Probably not up to snuff, but wonder how many brake changes include a brake fluid redo, Trust my guys say they do it and it is done, but know many just new pads and rotors if they need them.
@shadowfax My Acura says to use only Honda DOT 3. Non-Honda DOT 3 or 4 can be used in an emergency but then the system needs to be flushed as soon as possible. DOT 5 can’t be used. Just sayin’ that’s what the book says.
MY fluid already looks significantly dark after a year. I am in CA, so doubt it is much moisture, probably just debris from the system. On one car I got a bit lazy doing this and three calipers and one MC went out in a short span. It was a dodge, so not sure if that had anything to do with it.