RF5BPilot

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.

Edgy01

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.

Michael-Dallas

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.

dallison28

it doesn't matter how fast the car is, if you can't stop what good is that speed?

wwest

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.

jyoteen

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.

ivangene

+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???

Fissionx

Which fluid did you boil? I am using super blue and pagid yellows, as are many other people I know; but im always afraid blue isn't enough...

jyoteen

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)

Van

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.

Tippy

+996

AudiOn19s

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

Fissionx

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?

AudiOn19s

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

Ray S

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.