I have a Mazda CX9 and a CX3. Neither needs to ever have the brake fluid changed in the US. In Canada and Mexico they have to have it changed every 30,000 miles. The same on the rear transfer case fluid. AFAIK the parts, fluids, and road conditions are the same in all three countries. So; why do cars maintenance requirements vary by country?
I called Mazda, but they just tell me that both are correct, which doesn’t make much sense.
There seems to be a great deal of politics involved with maintenance requirements from country to country and even state to state. If the brake fluid is significantly flushed when brake repairs are done I see no need for scheduled flushing.
I’ll mention something I’ve noticed over the last few years
We have a lot of GM and Ford vehicles in our fleet, and for the most part, brake fluid flushes were never mentioned in the owner’s manual or the maintenance schedules, with the possible exception of severe use
That has begun to change. Ever more owner’s manuals and maintenance manuals are saying to change the brake fluid every 2 or 3 years
Clearly, brake fluid hasn’t changed much, but the industry’s attitude has, at least to some degree
I would err on the side of caution and do a brake fluid flush every 2-3 years, if it is NOT mentioned in the owner’s manual
If the owner’s manual says every 2 years, then by all means, follow it
In general, if you follow the severe service maintenance schedule, you’re doing fine
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My wife’s Mazda 3 has a maintenance manual that has different intervals for the US, Canada, Mexico ands Puerto Rico. Schedule1 is for Canada, USA and Puerto Rico and is the non-severe operation. It has 7500 mile oil change intervals for oil and filter changes, and 30,000 miles for cabin and air filters.
Schedule 2 should be followed by Canada and Puerto Rico users if any harsh driving environments are encountered.
Schedule 2 has more frequent oil and filter changes, 5000 miles,
Then there is a section for Mexican maintenance which is like schedule 1 with 10,000 kilometer intervals for oil changes and a Schedule 2 with 5000 km oil changes. Someone in Japan wrote this as the car was built there.
So the guy in Japan who wrote the manual thinks Mexico should adhere to “severe service” maintenance intervals?
That guy should come visit us, see some of our neglected roads, and the jack-rabbit type of drivers that are so prevalent. He’ll quickly change his mind and decide the US also merits “severe service” maintenance intervals 
Remember when whatever branch wanted to change recommended oil change interval upwards, just to manage oil use, not car life.
GM comes to mind
Every failed master cylinder, wheel cylinder & caliper I’ve seen were filled with nasty looking brake fluid.
For the last 2 cars and ~20 years I’ve been changing the brake fluid every 3 years; and no hydraulic part failures.
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That’s not been my experience
I’ve replaced plenty of failed brake masters, wheel cylinders and calipers on vehicles that had regular brake fluid flushes every 2-3 years
everybody’s experience will differ
Rod’s right, however I doubt of the average owner has any idea whether his/her brakes were adequately flushed when the brakes were done. Since so many mechanics still push the pistons back to add the new pads, never opening the bleeders, unless an owner knows that his/her bleeders were opened and the crappy stuff pushed out, I think an intentional flush with every brake job every three to five years isn’t really a bad idea. Regarding the Xfer case, 30,000 miles is perfectly reasonable.
People need to know that because something isn’t required to do doesn’t mean that doing it won’t prolong the life of its system components. Fluids and filters are an engine’s lifeblood. I used to go so far as to even change my truck’s differential fluid every now & again. That was probably going overboard, but I was young. Of course, I DID get hundreds of thousands of trouble free miles out of the trucks!! An occasional peripheral component, like the alternator or battery, would need to be replaced, but nothing serious.
I am wondering if the US recommendations is written so that the “cost of ownership” would be lower, or there is some EPA requirement to reduce the car’s carbon foot print and they are getting rid of certain maintenance items in the manual.
I also think having the “non-severe” schedule serves the same purpose. The list of conditions for severe driving encompasses every possible driving condition.
As for differential fluid service, I noticed something interesting
Ford, to name one does have a differential fluid service interval, but apparently only for severe service
We tend to ignore brake fluid service around here because the likely result of trying to open a bleeder is to break it off. Of course, the massive salt and chemical brines applied to our roads means that by the time of the second brake jog\b the calipers need to be replaced and then you get a nice new bleeder.
I just noticed when I type my reply it is duplicated in a second window to the right. Is this happening to anyone else?
It happens to me too. I just accept it. I know not what it means.
You can choose to show or hide the text preview, the button is in the lower right corner.
I was told the rear differential on our Acura needs to be changed at 10,000 miles, then at 20,000 after the first change. The transfer case gets changed at 30,000 with the trans fluid. No idea about the brake fluid but as others have said its a good idea every couple of years.
@bing I’d pay attention to that Acura/Honda recommendation of diff fluid. My Honda S2000, a RWD car, would actually get a little noisy as the fluid approached 30,000 miles and went away after I changed it. Never seen (heard) that before on any other car I’ve owned.
I think brake fluid changes were never recommended in the olden days because everything was steel or cast iron. Brakes from the 60’s didn’t have any aluminum components. Once those were introduced, now the possibility of galvanic corrosion as water builds up in the brake fluid is a reality. Also, I think boiling fluid is more likely with disk brakes than with drums.