Originally Posted by Godfather
Get a grip......... when was the last time you ACTUALLY had your brake fluid changed? The answer, for almost everyone, is never. Maybe, just maybe, if you had major work done to the brake system, somebody bled the brakes.
I read through this entire thread. I have to say, I used to buy into the "you must change your brake fluid every 2 years" mantra. Just like I used to buy into the "change your oil every 3,000 miles" song as well. The fact of the matter is, I believe these are things that used to be applicable in the "olden" days, but simply are leftover "truisms" that no longer apply to modern equipment.
Just like modern engines have better tolerances, run cleaner, etc., they can go much longer between oil changes. 5,000 seems to be the minimum manufacturer recommendation, with 7,500 and 10,000 much more common. As far as brake systems go, they system is sealed and air tight. If it wasn't, you'd get air in your lines and you'd have problems (and fluid leaks). So, where is this moisture going to come from? Even if the reservoir cap isn't totally air-tight (which would be a faulty cap in any modern equipment) how much air could possibly get through? And that air would have to carry water molecules with it. And since the fluid isn't circulating, what's exposed?
Even if the fluid darkens, that doesn't mean it isn't effective. People used to check your oil by looking at the color. With modern detergents in oils, your oil can look "dirty" in 50 miles. Does dark brake fluid mean it's not effective or that it's just changed color?
The thing that sealed the deal for me was when I was looking for some online info for brake service on my other vehicle (2004 Ford F-150). There was practically the very same discussion going on. There were people claiming to have never
changed their fluid and everything is working fine…well
past 100K miles. One person went so far as to claim that there was no recommended service interval
for brake fluid changes!
Well, that was it--I went straight to the maintenance schedule to prove this nutcase wrong. Surprise, surprise on me. There is no recommended brake fluid change interval on that vehicle. I checked every service in the entire book.
So that leaves me (and probably some of you) with a burning question: how can it be necessary to change brake fluid in one vehicle every two years or 20,000 (24,000?) miles yet not need to change it at all in another vehicle? By now, some of you might be thinking the fluid in my truck is DOT 5 so it isn't water-absorbing (hygroscopic for those of you who prefer the big words). Nope, it's DOT 3, the lowliest of all brake fluids.
So, I pose that question back to the group: how can it be possible that it's so important to change so often in one vehicle, but not ever necessary (sans replacing parts that would necessitate a change) in another?
For what it's worth, in all the vehicles I've ever owned, I never had a master cylinder failure, and I only replaced calipers once on an '82 Volvo I had. I did replace the fluid once in an Audi back when I was younger and thought that if I religiously replaced all fluids the vehicle would last longer. Well, I don't know if that's true, except I never have since and I've owned all of my vehicles well past the 100K mark.