Gator, why are you perpetuating myths?

Since 9 out of 10 people NEVER change the fluid, I guess that explains the all the collisions you and I see every day from brake failure.

Fact: Brake Failure is at the bottom of the list for cause of accidents... or shall we say, collisions. Leave your fear mongering at home, please.

I'm not saying to ingnore your brake fluid.
I'm saying DON't blindly change it every x miles because of some myth.

While what you propose is POSSIBLE, is not PROBABLE.

Just checked the brake fluid in my 20 yr old dodge truck with at least 10 year old fluid.
It has no ABS to worry about ( and wow, never been in an accident in 150,000 miles ) and the fluid was clear, like tea color. Since I rarely open it up, that's key to success.
Less chance for contaminaton. You have to be very, very careless to get dirt in there.
And mositure? Well, I live in CO. The average humidity is less than 20%.

Don't panic. Don't blindly change unless you have money to burn... you ARE wasting product. Don't be a chicken little. BE SMART. Change it if, and only if it needs changing.

I think 20 cars in "real world" conditions provide much more reliable data than chicken little fear mongering. Of course, your mileage may vary, especially if you live in a rain forest...

If it was SUCH A DANGER you would expect a sticker at least in your car. There are air bag warnings everywhere, but like others pointed out, hardly a mention anywhere about the brake fluid.

This is not your father's Oldsmobile.

 

GatroJ: I see some major issues with two of your articles...

From the second article...
"At $49, just two brake fluid changes a week can generate $31,000 a year in sales."

So the real reason for this article is to sell shop owners on a way to increase revenue... Sounds like a plant for brake fluid vendors. We should all drink lots of milk (Dairy producers of America), eat more pork (National Pork Board) and drive bigger more powerful cars (I don't think you need any help on this one).

From the third article...
"Statements made by the "Big 3" domestic OEM manufacturers that the brake fluid in their vehicles lasts the life of the vehicle"

So this seems to answers my question as to why brake fluid change is not mentioned in the Owner's Guide. Now why would a company, that recommends MANY other fluid and component replacements as part of best practice maintenance, not even mention brake fluid replacement and then go so far as to make statements that it's a lifetime fluid?

Please refrain from using hygroscopic in your answer...

 

Do what you want but I see many ABS system failures due to clogged valves or restricted screens. ( not cheap) On the rear wheel anti lock systems that are used on American trucks they have a nasty habit of clogging and the result is no rear brakes. Most people never realize this until they try to tow something and over heat the front brakes. All master cylinder failures are due to contaminated fluid, as they don't wear out, they corrode internally and cut the seals.

 

Mark, I'm not trying to be argumentative with you with my questions so please take it as me trying to understand the problems you mentioned.

What is clogging the valves or restrictive screens? Is it debris in the lines? If so, does it come from the reservoir? Otherwise, we're dealing with a sealed system, right?

I can see where water in the fluid could cause corrosion in the master cylinder and thus cut the seals (similarly, this happens a lot on hydraulic pistons that are exposed to the elements, like those on heavy equipment). I've had this happen on cars that were parked for LONG periods of time (like my 75 MG).

 

All ABS systems use valves to isolate the wheel and usually another valve to modulate the brake pressure. Usually there are 2 per wheel so a 4 wheel anti lock system will have 8 valves 4 isolation and 4 modulation. The screens are little fine filters that go ahead of the valves. I don't know where the particles come from, I suspect it is a coagulation from the brake fluid and moisture. It might also be aluminum salts from the saturated brake fluid reacting with the aluminum parts. I find this almost every time the brake fluid is dark almost black. We call it the fluid of death. I flush my brakes every other year not because I think it might be beneficial, I know it is, my 30 years experience tells me so.

 

In years past, before owning/parking in an attached garage, my brakes would absord more moisture and my first indication of something wrong would be leaking wheel cylinders, because the contamination/rust in the lines would ruin the seal(s) slowly. For the past 17 years I've been parking in a nice dry garage, and that problem has practically disappeared.

So the comment John GPSMAN1 made about climate is valid in my opinion. If you and your auto live in a much drier environment, I think your brake fluid flushing interval can be extended much longer. If you live in a much wetter climate and/or you car sits outside 24/7, I think you'll pick up more moisture quicker, and that periodicity will increase.

IMHO mileage is not a good indicator. Time, environment, and use or abuse, have more to do with brake fluid life span.

 

Do you any citations to back that up?

Anecdotal evidence isn't very reliable, but looking at my own service records and manufacturer service manuals, I see no mention of changing brake fluid after X miles. I do see mention of changing brake fluid after a given period of time.

Suzuki seems to think brake fluid needs to be changed every two years. Honda (motorcycle) is giving me two years for the fluid in the brake system and three for that in my hydraulic clutch. My old Ford Tempo was on a five year schedule, but I was in school back then so who knows if I was following the schedule or just getting it done when I could afford it.

Just a guess, but I'd say these numbers are coming from the manufacturers own estimates of just how well sealed their systems are. In any case, a general recommendation isn't a replacement for an educated decision.

 

From the third article in GatorJ's post:
"One of the task force members involved with the OEMs found out one of the OEMs did a study using test fleets comprised of thousands of vehicles from various locations that were approximately 8 years old. They tested the brake fluid for moisture and discovered an average of less than one percent over the entire fleet."

Maybe this is why there's no set flush interval in the owner's guide? I'm sure there were vehicles in the study that did need flushing but a fleet average of <1% seems to indicate the general public's fluid isn't as degraded/dangerous as some might think.

Could this lack of moisture content be due to specific steps this OEM manufacturer took to make the brake system less permeable? If so, is this technology more widespread in 2008 models or in those with more advanced (or at least more engineered) systems like the FEH/MMH/MTH?

Once again, I'm just trying to make sense of what appears to be a divided audience here regarding this subject.

 

This is probably the reason Texas at least the eastern half is pretty humid. I don't work on cars from low humidity areas, ergo my experiences. I do have a brake fluid tester that measures % water and most cars I check have 2-3 % moisture content. And it takes about 2 years to get to 2%

 

My worst experience with contaminated brake fluid was on an old motorcycle years ago. The moisture content was enough that in the cool morning, the brakes seemed normal. But after the cycle sat in the hot sun all day, and after several brake applications. Moisture in the calipers expanded the pads against the caliper, the wheel(s) locked up on me, brought me to a screaming halt.

Flushing the system with new fluid corrected the problem, and made a believer out of me