[RidgeRunner0207]

Brake fluid attracts moisture, brake fluid is very corrosive, heat effects the fluid just as it would any oil/fluid.

There is a valid reason to keep it fresh every two years, if you do not adhere to the recommended schedules for service PAG may deny a warranty claim in your brake system due to service neglect.

Its under $300 at the dealer and its then documented in their system, I could have changed mine myself last year, but it would not have been noted in the Porsche system as to the date and mileage it was performed, so I had them do it so that it was documented.

Some things you just get done, its a upfront cost to ensure a down the road warranty on the brake system.

 

[CourtneyNYC]

Makes perfect sense and refreshing brake fluid is one of those items many, among the non-enthusiast ranks, are not even aware of.

 

[iconoclast]

Brake fluid attracts moisture, brake fluid is very corrosive, heat effects the fluid just as it would any oil/fluid.

There is a valid reason to keep it fresh every two years, if you do not adhere to the recommended schedules for service PAG may deny a warranty claim in your brake system due to service neglect.

Its under $300 at the dealer and its then documented in their system, I could have changed mine myself last year, but it would not have been noted in the Porsche system as to the date and mileage it was performed, so I had them do it so that it was documented.

Some things you just get done, its a upfront cost to ensure a down the road warranty on the brake system.

My question has nothing to do with warranty.
I realize that if everyone tested their brake fluid @ 2 years, the vast majority would have moisture. IDK if it would be 1%, 3% or 5%. So, it is a moot point for most.

Maybe some would be able to change it every 3 years if not living in a humid climate

I was wondering about literally same moisture content (0%) @ 2 years as just after changing the fluid.

Everything I can find in Google searches talks about moisture.

I think a lot of scheduled maintenance items are questionable. Not whether to do them but WHEN. Especially the ones that have time & mileage, whichever comes 1st.

For me:
Oil is easy, synthetic every 1 yr. even if put on only 5K miles. (Yes some want to analyze their old oil & change it every month

Engine air filters s/b mileage & not time. A Garage queen’s air filters are NOT getting dirty sitting in the garage!

Spark plugs, also mileage, not time. I’m going to do mine @ 30K miles Which will be > 4 years. (Porsche mechanic also said he thinks that is OK)

PDK fluid? IDK I asked a Porsche mechanic & he reiterated the official position of 4 yrs. or 40K whichever comes 1st but admitted if it was his car, he’d wait till 40K miles. I’m not sure yet what I’ll do.

Wipers? Give me a @##$***!! break! Whenever I do not like how they wipe, LOL. Probably s/b changed every 6 months in this heat <GRIN>

 

[Beardy]

With the small price paid to change your brake fluid and we are talking about a premium priced vehicle, I really don’t get why this topic even gets discussed

 

[iconoclast]

With the small price paid to change your brake fluid and we are talking about a premium priced vehicle, I really don’t get why this topic even gets discussed

You're discussing it. Why?

 

[Glock19]

Anything that's not required service in the manual, I tell my service dept(s) to get bent unless they can make a REALLY compelling case for it.

 

[Shark]

With the small price paid to change your brake fluid and we are talking about a premium priced vehicle, I really don’t get why this topic even gets discussed

Seems like a very reasonable question. Not sure why it would vary whether it pertains to a $20,000 car or a $100,000 car.

I have the same understanding...the reason Porsche (and other manufacturers) call for a brake fluid change every 2 years is because the fluid tends to absorb moisture, and that moisture can damage some of the parts in the brake system.

So if you live in an extremely dry climate, does brake fluid need to be changed with the same frequency? I'm no expert, but it seems to make sense.

If I lived in Phoenix I might buy one of the testing kits and check the fluid for moisture annually, and I would keep the receipt for the testing kit in case a dealer attempts to deny a brake warranty claim.

RidgeRunner makes a good point about the warranty, but I would take that risk as IMO the chances of a brake system warranty situation where the dealer would claim it was due to not changing the fluid (especially in Phoenix) is pretty remote.

I'm also not in the least afraid to take on a dealer and/or manufacturer when a warranty claim is wrongfully denied, and I've done so in the past. My experience if they see you are knowledgeable and are not going to let them roll over you, most will immediately do the right thing, and if not, they will the minute they recognize you are not hesitating to engage legal counsel.

Sucks that you might have to resort to that, but it's the way it is.

 

[jzwu]

If you live in a dry climate, do the flush every 3 years. Otherwise, every 2 years.

I live in a relatively dry place with not much rain & no snow so I do it every 3 years for all my cars. Never a problem.

 

[Steve B in SD]

I doubt very seriously changing the brake fluid is as critical as some make it out to be. It's not a bad idea, to be sure, and for a car that sees track duty, it should be considered a mandatory maintenance item.



But is it really necessary for a street only car?


Consider this: Every manufacturer has maintenance schedules for the vehicles they make, ALL have engine oil & filter changes required, trans oil changes, diff oil changes, coolant changes, and transfer case oil changes. Pretty much all agree on changing engine oil, some list transmission & differential oil as optional depending on operating conditions, same for coolant intervals, etc. However, there is little agreement as far as changing/flushing brake fluid. We all know Porsche and Mercedes recommend changing brake fluid every two years, as do most motorcycle manufacturers. However, looking through the manuals for my Nissan and my Kia, neither has any requirement listed to ever change the brake fluid under any circumstances. The only mention of brake fluid in the maintenance manuals is simply to check the level.



So, if changing the brake fluid was truly a life saving maintenance item, and you're going to die in a horrible wreck if you don't change it, there would be universal consensus among manufacturers as to the idea of changing it along with required intervals. Since it appears not to be a universal maintenance item for all manufacturers, much the same as changing the engine oil or any other part of the running gear, you have to wonder how necessary it really is for a street driven car. After all, the liabilities are the same for all manufacturers, and lawyers like to keep ahead of possible legal problems, so you have to assume if changing brake fluid was really a critical maintenance item it would be universally required for all cars.



Every auto maker tells you to change tires when the tread is down to the wear indicators for obvious reasons, it's a universal, no questions asked kind of thing. But, for some manufacturers to have NO requirement to change brake fluid, and others to say it's absolutely necessary every two years has to call into question the true necessity of it as a maintenance item, right??

 

[jzwu]

You are missing the point of different types of brake fluid requiring different maintenance.

Most non performance cars use DOT 3 brake fluid, which is less prone to absorbing moisture than DOT 4 fluid used by many performance cars, such as BMW and Porsche. DOT 4 fluid has higher boiling points thus better performance, but it absorbs moisture more easily.

 

[rcristobal]

I had the brake fluid changed at 19k done by dealer along with 20k service on my 2015 Macan and notice an improved in braking especially the initial bite.

 

[Beardy]

Seems like a very reasonable question. Not sure why it would vary whether it pertains to a $20,000 car or a $100,000 car.

I have the same understanding...the reason Porsche (and other manufacturers) call for a brake fluid change every 2 years is because the fluid tends to absorb moisture, and that moisture can damage some of the parts in the brake system.

So if you live in an extremely dry climate, does brake fluid need to be changed with the same frequency? I'm no expert, but it seems to make sense.

If I lived in Phoenix I might buy one of the testing kits and check the fluid for moisture annually, and I would keep the receipt for the testing kit in case a dealer attempts to deny a brake warranty claim.

RidgeRunner makes a good point about the warranty, but I would take that risk as IMO the chances of a brake system warranty situation where the dealer would claim it was due to not changing the fluid (especially in Phoenix) is pretty remote.

I'm also not in the least afraid to take on a dealer and/or manufacturer when a warranty claim is wrongfully denied, and I've done so in the past. My experience if they see you are knowledgeable and are not going to let them roll over you, most will immediately do the right thing, and if not, they will the minute they recognize you are not hesitating to engage legal counsel.

Sucks that you might have to resort to that, but it's the way it is.

I think the value of the car is relevant in that the cost to do a fluid change would be similar between the two vehicle price points but the potential repair costs will be significantly more in the dearer vehicle so your playing with bigger stakes. To keep it in perspective we are talking about the cost equivalent of a tank of fuel a year to maintain this aspect of your vehicles warranty.
I don’t know if keeping the receipt for a test kit is sufficient evidence that you used it and the result of the test? Maybe it is but if there was a brake issue and they tested the fluid and found moisture and you have not followed the maintenance schedule I think you would be on your own regardless of what your $10 kit told you six months prior.

Is a claim wrongfully denied if you haven’t maintained a product in accordance with the manufacturers manual? I know it has to demonstrated that the fault was caused by the item you have not complied with but you leave yourself vulnerable to these issues when you do not uphold your end of the agreement.

At the end of the day I guess you way up the risks V the cost and make your own call. For me it is a small price to pay for peace of mind.

 

[wwahl]

Changing the brake fluid gets rid of the acids that eat away inside the slave cylinders. I have been up close and personal with this issue with my Ducati motorcycles. When the bores get eaten up the rubber parts go fast. Every time you run your car the brakes get super hot then get cold after you park. Cycle that thousands of times and the brake fluid goes south. It isn't just moisture.

 

[gccch]

brake fluid flush

How important would you say is the 2 year/20,000 mile brake fluid flush?

For the Macan and Cayenne, is this really a crucial maintenance cycle?

 

[DanNYC]

Changing the brake fluid gets rid of the acids that eat away inside the slave cylinders. I have been up close and personal with this issue with my Ducati motorcycles. When the bores get eaten up the rubber parts go fast. Every time you run your car the brakes get super hot then get cold after you park. Cycle that thousands of times and the brake fluid goes south. It isn't just moisture.

What acid are you referring to? Is brake fluid acidic to begin with? Or perhaps it becomes acidic with use? Never heard of this before.

 

[DanNYC]

IMO changing brake fluid based on testing is far more accurate than just changing it based on a time interval. I’ve had brake fluid that did not need to be changed until it was 5 years old, and I’ve had brake fluid that needed to be changed after only a year.

Not suggesting not to change your fluid when it needs it, but when was the last time you heard of am in warranty brake system repair where it could have had anything to do with not changing brake fluid? This is very rare anymore.

Problems caused by brake fluid not being changed as needed tend to show up way down the road as the car gets much older and almost is always out of warranty.

 

[flash gordon]

In this day and age, we are still using stone age technology brake fluid. I wonder what's so hard to come up with fluid that does not absorb moisture. It's a simple hydraulic system. Why can't the brakes be adapted to use hydraulic fluid? Then I thought that the brake fluid makers would shoot themselves in the foot if the fluid need not to be changed often. Of course, the service shops will see a big drop is sales also. What a racket!

 

[grim]

If there is 0 moisture in my brake fluid, do I ever need to change it?

Maybe, maybe not. At two years a dealer said no need to change the fluid in my 911. But they did at 3 years. Part of this might be the ABS. Those complaining that the "never had to do this before", were they in pre-ABS days? From 2005 Despite the talk, brake fluid is not forever https://www.chicagotribune.com/news/ct-xpm-2005-11-20-0511200182-story.html

"ABS is very sensitive to foreign matter in the hydraulics. The foreign matter comes from corrosion in the brake system. ... Though there are corrosion inhibitors in the fluid, they wear out over time; up to 90 percent is gone in as little as three years."

I can believe this. Nothing is forever. Brake Fluid is a consumable.

In this day and age, we are still using stone age technology brake fluid. I wonder what's so hard to come up with fluid that does not absorb moisture.

DOT 5 does not absorb moisture. Why doesn't Porsche use DOT 5? I guess you have to ask Stuttgart.

I doubt very seriously changing the brake fluid is as critical as some make it out to be. It's not a bad idea, to be sure, and for a car that sees track duty, it should be considered a mandatory maintenance item.

But is it really necessary for a street only car?

... looking through the manuals for my Nissan and my Kia, neither has any requirement listed to ever change the brake fluid under any circumstances. The only mention of brake fluid in the maintenance manuals is simply to check the level. So, if changing the brake fluid was truly a life saving maintenance item, and you're going to die in a horrible wreck if you don't change it, there would be universal consensus among manufacturers as to the idea of changing it along with required intervals.

Brakes are about THE most important thing on the car. Porsche takes it very seriously. You can look it up but they are serious about testing them. They are always more powerful than the engines. Water in the brake lines means the boiling point goes down. According to this article, 3% water in DOT 3 means a drop of 100 degrees in boiling point. Since Porsche is a performance vehicle, I'll guess they expect people to drive hard and brake hard. Sure, some people buy status symbols but as Ferry Porsche once said: "My cars are meant to be driven, not polished". If water in the fluid, the brakes will fade and then ... crash.

Those Kias and Nissans? Who drives them hard? Who brakes hard on the street? Only in an emergency? So, what is the probability of person A in a Porsche and Person A in a Kia braking hard, day after day? Have you ever seen anyone really use their brakes in a Nissan or Kia? I don't mean once in a great while because of an emergency but brake hard in turns or coming up at lights?

One of the things you learn, and I'm not 100% sure about the Macan but it probably is, but I know it for the 911, is that the brakes are very, very good. VERY good. They are so good that coming up to a light, I purposely keep looking in the rear view mirror because although I knew I could stop in time, that was not true for the person behind me. This wasn't a one time thing. It's ALL THE TIME. Every light, every stop, always look in the rear view mirror.

Brakes don't fail very often. Per the NHTSA in 2015, usually, by a wide margin, its driver error but 2% for mechanical failure. Of that 2%, 22% was for brake failure. They don't break it down anymore than that so for all crashes recorded and documented in that year, .0044% were due to brake failure, ~10,000. It doesn't say "why" the brakes failed. It could be a defective part, brake fade, mechanic error. Who knows. So this is where the numbers come in and this is speculation but I'd bet you could look this up and find something from people who do crash forensics or insurance companies.

The carmaker, tells you the maintenance to do. You think its a scam. "I ain't paying for that. They just want my money". And then there is my favorite that is expressed in this forum over and over again.

"But my (Kia, Toyota, VW, .... car) never did this". This is repeated over and over again. Different subject, same tune. Then go buy a Kia, Toyota, VW ...

So, you don't have the fluid checked out and water has gotten into the fluid. One day, you're trucking down the interstate doing 75, whatever the speed limit might be and some construction comes up fast. You brake HARD. All is OK. You slow down to a stop, then traffic flows again. But construction is constant. You brake hard again from 75 and then get back up to 75 and ... a deer runs across the road. You brake HARD again and .... mush ... crash.

Whose fault is it? Did the brakes have a faulty part? Or did that driver just ignore the maintenance schedule. When the crash forensics are done and the conclusion is water in the brake fluid, who is to blame? Porsche? Did Porsche build defective brakes? Your mechanic? Did the last mechanic who worked on the brakes do something wrong? Or the owner? Did the owner decide brake fluids were a scam and chose to ignore them? Who will be assigned responsibility for the brake failure? Now imagine it wasn't a deer but a minivan full of kids. Are you feeling lucky today?

It's a couple hundred dollars. It's a couple nights out for a fancy dinner for two every other year. Why is anyone questioning this?

My suspicion on why its not in a Kia or Nissan manual? Who drives them and how do they drive them? Its a numbers game. How hard do those drivers brake vs Porsche drivers? What are the probabilities? Is the driver in a Kia or Nissan traveling at high speeds the same as the Porsche driver and braking as hard from higher speeds?

 

[RidgeRunner0207]

Seems like a very reasonable question. Not sure why it would vary whether it pertains to a $20,000 car or a $100,000 car.

I have the same understanding...the reason Porsche (and other manufacturers) call for a brake fluid change every 2 years is because the fluid tends to absorb moisture, and that moisture can damage some of the parts in the brake system.

So if you live in an extremely dry climate, does brake fluid need to be changed with the same frequency? I'm no expert, but it seems to make sense.

If I lived in Phoenix I might buy one of the testing kits and check the fluid for moisture annually, and I would keep the receipt for the testing kit in case a dealer attempts to deny a brake warranty claim.

RidgeRunner makes a good point about the warranty, but I would take that risk as IMO the chances of a brake system warranty situation where the dealer would claim it was due to not changing the fluid (especially in Phoenix) is pretty remote.

I'm also not in the least afraid to take on a dealer and/or manufacturer when a warranty claim is wrongfully denied, and I've done so in the past. My experience if they see you are knowledgeable and are not going to let them roll over you, most will immediately do the right thing, and if not, they will the minute they recognize you are not hesitating to engage legal counsel.

Sucks that you might have to resort to that, but it's the way it is.

I service my own vehicle, my Wife's Nav has been having fits for the past 6 months on and off, the dealer finally discovered that the rear sunroof drains were spilling over slightly causing the module for the rear park assist and rear camera to get all wacked out..............

Porsche denied me warranty on both modules, WHY, because even though I maintain the drains, because it was not documented and was getting wet, they assigned blame to that !!!!

So roll the dice on a less than $300 brake flush, when the system has an issue, they may or may not deny you a valid claim.

Its going to cost you one way or another, so I spent $300 last fall on the flush just to avoid a brake system denial of warranty, I also spent the $$$$ to have the spark plugs changes @ 30K miles, because it was worth it to not have to do it and have it documented..........had I known they would play games with teh drain cleaning I would have spent the $250 or so to have that documented.

The tech dried, cleaned and reinstalled the module 2x's before it worked again, being it was $1400 just for one module, the dealer good will no-charged the drain cleaning and documented it as a courtesy service.

Things that make you go hmmmmmmmmmmmmmmmmmmm

 

[Shark]

I've long assumed the reason for changing brake fluid on a street vehicle was to protect the system components from deterioration from moisture, such as metallic brake lines. Wrong?