34 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHBrake Fluid Flush Needed Every 24 Months?
Leading reported evidence
Install too
Performed · outcome unconfirmed
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Leading evidence: 'Install too' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, the most frequently mentioned possible cause is 'he's wrong' (1 discussions; 0 report identifying it and 1 suggest it). The most frequently discussed action is 'Clean .pdf' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that suspect a cause
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suspected cause
I would hate to find out the hard way that he's right about crystalizing - although I suspect he's wrong...
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
My brother in law is in the auto repair business and stated that the heating up and cooling down of brake fluid over time will absorb moisture, the bane of these metal systems.
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
My brother in law is in the auto repair business and stated that the heating up and cooling down of brake fluid over time will absorb moisture, the bane of these metal systems.
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
Also, bear in mind, that by flushing your fluid every 2 years, it not only replaces the fluid, it also removes air bubbles in your line; when you boil your brake fluid (i.e.
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
Yet, if you look at the fluid coming out of the system (especially the fluid close to the calipers), you'd see a definite color change through use and absorption.
Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
34 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.
0 acknowledgements have no verified action link; they do not establish a repair result.
Generation: 20261026T172408Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
My dealer is pushing me to get a brake fluid flush 2 years after my 30K service (but only about 6K milage). Claims the fluid could crystalize.
Necessary or just a service marketing push?
Not a service marketing push.
Brake fluid absorbs moisture, which in turn will lower the boiling point of the brake fluid by as much as 30%. The excess water moisture can cause valves to corrode and stick. The moisture can create a rusty sludge that can clog the valves and pistons in the brake system.
But don't take my word for it, check out these links. They are worth 5 to 7 minutes of reading.
http://www.brakefluidtester.com/downloads/clean.PDF
http://www.type2.com/library/brakes/brakef.htm
It should be done with some frequency, but every 2 years is probably overkill for street driving. I've done it as a warranty precaution. I do it myself. Takes less than an hour and costs $12 for the fluid. I don't even need to take off the wheels. I can reach both bleed valves through the wheel spokes. Probably not possible with your wheels. Never heard of brake fluid crystalizing.
'Every 2 years' has been the factory service interval for my other vehicles [Audi/Lexus]. I would have it done.
Don't have it with me - what's the OM say? I think every 2 years.
The braking system is one of the most important operating systems of the car. An ounce of prevention and all that jazz. Besides, it's not that expensive, even if the stealer does it. I would hate to find out the hard way that he's right about crystalizing - although I suspect he's wrong...
-td
Would someone explain to me how, in a SEALED system designed to sustain pressures of up to 3000 PSI, the brake fluid will absorb enough mositure to compromise the braking capability in less than 10 years or 100,000 miles..??
Another case of the dealers promoting "urban legends" in order to line their pockets.
The amount of moisture absorbed by the brake system is greatly exagerated, especially in today's cars. Bleeding the system or removing the cap on the resevior allows moisture in. Any air space in the system, such as in the resevior, contains moisture.
Other than an opening on the non pressurized side of the system, if you are absorbing moisture in your brake system, then it is also leaking fluid.
moisture builds up in the system from condensation in the reserviour. This moisture will lower the boiling point and will allow the brakes to fade at a much quicker rate compared to newer fluid. Brake fluid should be changed around the factory intervals, but i would prob say 3-4 years and 30-40k would be sufficient for most vehicles. I flush the brake fluid in my vehicles myself. It is pretty easy and the wife usually helps to depress the brake pedal.
With todays systems, as someone posted are pretty well sealed, but again b/c of the close proximity to the motor and location in the engine bay, will get some condensation.
I have only had cars as new as 2002, so things may have really changed.
If its the 'systems' that are so well designed and sealed, then why use different fluids and maintenance intervals for track vs. street?
I've always been told that its because track brake fluid is more hygroscopic, and absorbs moisture more quickly than 'steet' brake fluid.
What's correct?
In my case, I'm sticking to the OM and warranty guidelines.
The increase in the "DOT" specifications over the years has increased the boiling temperature of the fluid. Track brake fluid gets much hotter than street fluid.
Good point about a closed system. Is that little pocket of air in the reservoir enough to "moisturize" the whole system? Maybe not.
I would think that changing the fluid has more to do with degradation. Anything over time degrades. The brake fluid is continually pressurized/not pressurized, heated/cooled, pulled in and out of little spaces and tubes. I am sure it breaks down in time. In 2 years? Maybe, maybe not. Bleeding the brakes is a cheap enough thing to do I'd rather not test it.
I will give you my personal story. I was at the drag strip running my '87. There are 2 turn offs for the end of the track. Well me, thinking "hey, I got a Porsche, I can make the first turn off from over 120 MPH". I did but once I turned and tried to apply the brakes for a second time, the pedal went to the floor.
I was baffled because the pedal soon built pressure back up. I was telling my Dad about it and he said "duh, you boiled the brake fluid".
Knowing my friend hadn't changed it in years, he was spot on. The moisture builds up and displaces the fluid which can easily boil causing air pockets.
Not good for hydraulic systems needless to say......
Traditonal brake fluid (i.e., not silicone) is hyrdophilic -- it attracts and absorbs moisture. While some of it happens at the reservoir, moisture also passes into the system when the brakes are used in the rain and the pistons are working back and forth. The result is boiling at the calipers under hard braking, which causes steam, which compresses (unlike fluid), which results in a loss of braking ability (seems like fade). More often, you never get measurable fade but do get corrosion in the calipers.
When I was in college, I had to replace both front calipers on a car because I didn't know to replace the brake fluid. (I too made the assumption that the system is "sealed." Just because brake fluid doesn't leak out, doesn't mean that moisture can't get in with the pistons working back and forth in high moisture conditions.) It only needed to happen to me once -- never again. Just like how often you change your oil can be a point of discussion, every 24 months is probably, slightly conservative and simply assures that you are unlikely to have corrosion and damage if you do it that often. Yet, if you look at the fluid coming out of the system (especially the fluid close to the calipers), you'd see a definite color change through use and absorption. Considering all that's at stake, this is cheap insurance.
Two perspectives from two I trust.
My brother in law is in the auto repair business and stated that the heating up and cooling down of brake fluid over time will absorb moisture, the bane of these metal systems.
My buddy the race car driver (for over 40 years) doesn't even replace the fluid in a couple of his race cars except maybe every 4 years,--he says it's overkill, particularly for the street.
I will do mine at about 36,000 miles when I get there,--which will be about 2-1/2 years from delivery date.
In 2 cars that I have purchased in the past, both from non-enthusiasts, the first thing I did was flush the brake system -- when the fluid in the reservoir looks like coffee, there is no question that it's time. Anyway, part of the reason why the fluid looked like coffee, in both cars, was because of the particulates/sediment that had formed over time. It really looked like somebody took graphite powder and dumped it in the brake fluid.
For my street/track car, I flush with Castrol SRF and I do it maybe once/year. Castrol SRF has a very high
dry
boiling point, but more importantly, it also has a very high
wet
boiling point. For all intents and purpose, wet boiling point is more important for me because brake fluid will start to absorb moisture as soon as you break the seal in the a bottle of brake fluid.
For my street cars, the 2 year recommendation w/ factory fluid is fine for me.
Also, bear in mind, that by flushing your fluid every 2 years, it not only replaces the fluid, it also removes air bubbles in your line; when you boil your brake fluid (i.e. at the track), it can leave air bubbles in your brake line giving you that mushy pedal feeling.
I would think that this is most certainly possible if his brakes never run hot. There is 2 types of brake fade, pad fade and fluid fade. Pad fade occurs when the pads overheat and the binding chemicals gas out; fluid fade occurs when you boil the brake fluid (refer to my dry/wet boiling comment above). If your friend rarely boils the brake fluid, then he would have little worry. But the way I see it, flushing the brake system is like an oil change.
///Michael
EDIT:
Here
is an excellent article hosted by Stoptech and written by Carroll Smith.
Track time will often result in your entire braking system be severely HEATED, making it a good idea to dispose the potentially BURNED brake fluid on a more often basis.
i can't believe this is up for debate. I guess everyone here believes in the Lifetime coolant business too.
Flush the goddamn brake fluid. It's pennies.
I take my car to the track so I bleed it every time I go to the track. I've boiled fluid and it's no fun hitting the brakes at a buck twenty and thinking it's gonna suck when one runs out of the escape road.
+1
All cars stop eventually, I would prefer to be able to decide when and where this happens.... And for a few bucks, even if its not needed... isn't it worth never finding out it was needed???
oh, this was the OEM fluid, but then again, I hit the 1000 mile break in at the paddock entrance to buttonwillow
I use Motul since SRF is a bit rich and I have yet to boil the Motul (and I do on average about 6 flushes per year)
Maintain your brakes like your life depends on it... because it does.
I do mine annually. I have a power bleeder, so it takes less than an hour and a liter of fluid is $15.
Get rid of the Blue. I boiled ATE Blue and GS610 this year. I've NEVER had an issue wtih Motul 600 or 660 though. Even when I severly overheated my stock pads one time I never boiled Motul. I tried the other two as a cheaper alternative and ended up bleeding brakes during the lunch break several times as a result. This was all with 997 GT3 ducts installed too.
I'm gonna splurge this year and just get the Castrol SRF combined with cup car ducts be done with it.
Andy
Yeah, I only used Motul 600 in my previous car and never had any problems, but was told by several that blue was fine for the 996.
Is there an easy way to flush the ABS unit as well? I hate spending an hour to get a perfect brake pedal only to get into ABS ONCE, and have it go to crap. What electronics or tools would I need?
No. I've never experienced this as an issue on this car though. Only ever got into the ABS once with the 996. That was on street tires and when I made a dumb mistake.
Andy
I've boiled the stock fluid before but never ATE Blue. Ate is fine as long as you change it regularly (high dry boiling point), but it is not as good as others when "wet". I use Castrol SRF now. It's $$ but it is much better than Motul and ATE.
Yeah, but he said easy.
There are machines that you can hook up to the car that will cycle the ABS unit without the car moving so you can do your flush in one simple go-around...none are readily available for the 996.
Adny
Not "lifetime" but I changed out the factory coolant in my '92 LS400 after 14 years and 120,000 miles although the freeze level was still good as was the PH factor.
Was looking just a bit dirty.
This is a source reference. Confirm exact model applicability in the original material.
