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The first time I heard about this was my 2011 370Z Im like are you kidding me. I never did it to any of my other cars at 20k or probably ever.
My 2017 has 17k miles on it, are the Porsche gods going to come down on me if I dont do this?? Whats the real on this?
The first time I heard about this was my 2011 370Z Im like are you kidding me. I never did it to any of my other cars at 20k or probably ever.
My 2017 has 17k miles on it, are the Porsche gods going to come down on me if I dont do this?? Whats the real on this?
Brake fluid flush should be performed every two years, regardless of miles. Most OEMS recommend it in multiples of 20K miles.
For 991, the prescribed interval for brake flush is every 2 years.
If you think that's too aggressive, alternatively you can get a brake fluid tester and wait until the moisture content warrants a flush.
Regardless, the next time you have brake work done - pad or pad+rotor change - the brake fluid will be flushed anyway as part of the job. This is also probably why on your other cars you "never" did a brake flush separately - it was just done in conjunction with other brake work.
What is the potential downside? If too much moisture accumulates in your brake fluid, it could cause corrosion in any part of your brake system that's metal - the calipers, the master cylinder, etc. Your personal risk tolerance profile will dictate whether the chance of that happening is outweighed by paying the cost of a flush every 2 years.
Speaking in worst-case? Water buildup in the fluid starts the corrosion. The fluid isn't necessarily constantly cycled in and out of the reservoir, so testing your reservoir for moisture content may not tell the full story. Flushing ensures healthy fluid.
In reality? Probably a non-issue, especially if you have your car in a climate controlled garage most of its life.
Either way, for the cost of a tank of gas and a few minutes of your time it's cheap peace of mind.
I'm not as mechanically capable nor knowledgeable as most here, but my take from less mechanical sense:
1. For wear items like tires, brakes, etc. drives can base it on wear. Life will vary based on how car is driven. For brake fluids, air filters, etc, manufacturers need to prescribe something since those aren't as measurable. Rather than best case scenario or even average, they'll have to err on side of caution and prescribe worse case scenario.
2. Mainstream cars aren't being pushed to the max like performance sports cars. Less tolerance to allow performance cars to "only" perform at 90%, since they have to live up to users who may track their car.
3. Mainstream cars with non-enthusiast owners are going to care less than performance cars with deeper pocket and more particular owners. Majority of car owners aren't going to read 20 pages stressing out over 0w40 vs 5w40 and doing multiple oil sample analysis. Porsche can get away with recommending users with more stringent intervals, not to mention Porsche tax.
Not making any recommendations, but I feel brake fluids service interval aren't as cut and dry.
I've owned a lot of .............um..............."well used" cars in my long lifetime. Old style drum brakes on neglected cars I used to buy nearly always had one or more slave (can you still say "slave") cylinders which leaked. In every case, the leak was caused by corrosion of the bore resulting from moisture. The cure was to hone the bore (if it wasn't too bad) or replace the part and install new seals. This could have been avoided by an occasional brake fluid flush because brake fluid absorbs moisture from the air. Living in a dry climate may reduce the problem but it won't eliminate it.
Disc brakes suffer similar problems when neglected, but they're much more expensive to repair.
Flushing the braking system involves nothing more than extended brake bleeding, a simple task that owners should perform more often than they do. You can do it with nothing more than a small wrench, a piece of tubing, a tin can and a helper. But one of the brake bleeding devices which work on either pressure or vacuum makes it a simple one man job. All you really have to know is "lefty loosey, righty tighty". Instructions and videos are all over the internet.
The process is easy and especially cheap when compared to the consequences of dealing with component corrosion later on. This is where an ounce of prevention really is worth a pound of cure. You will be rewarded with a braking system which will last for many years plus a nice firm pedal and improved braking performance.
If you're totally incapable of doing this simple task yourself, hire the gear-head teenager living down the street.
Our cars use DOT4 fluid which absorbs water at a higher rate than DOT3 which is found is most cars. 2 years is probably the safe bet, but it’s really dictated by moisture content.
As many have stated, it’s a straightforward job, so it’s worth it to have it done as part of your regular maintenance. Cheap insurance
As pointed out the brake fluid flush is recommended by Porsche every 2 years. I tend to have all recommended service done, keep records with the idea that the car will run trouble free and with documented maintenance will have a higher resale value. Additionally I like having a certified technician look over the car at least once a year. Many on this forum have the knowledge, tools and the enjoy doing their own maintenance and some of us do not. Brake fluid flush is not very expensive and cheap insurance whether you do it yourself or pay a professional.
During the CPO of this car November of 2019 they did new front pads and rotors. Based on that it would seem as if Im good for another year. I will do the moisture test and Youtube up on the flush process.
On my motorcycle I replace the fluid in each reservoir yearly, not a full flush but has worked for me over a 20 year period on the same bike and mileage is sadly minimal.
I have always done my flush every two years, more often if I track the car. I learned this the hard way by not keeping up with one of my cars.
It's not just the brake fluid that goes "bad" it's the components that can corrode and fail because of it. That can get VERY expensive if something else fails or starts to have an issue because of moisture.
In the end, it's just insurance that nothing goes wrong.
The 2 year recommendation is universal to most if not all manufacturers, regardless of types of vehicles, sporty cars or minivans. As others have mentioned, brake fluid is hygroscopic, so you may lose some braking power if the fluid gets too hot and boils, which is typically when you need it most. Is it important? For most people...no. That really depends on how you use your car and where you live. But the engineers can't tailor the recommendation to who's buying the car and where they live, so they recommend the most conservative maintenance.
Having said that, I try to abide by that rule, but have stretched it out to 4 years...by then the fluid color is really yellow/brown compared to the fresh fluid. At that point, I'd be really concerned that the fluid will not function as originally designed if I track the car or live in the mountains where brake performance is crucial. But I live in MN, and don't track, so extending the service is acceptable risk - for me. YMMV.
02-21-2021, 11:27 PM
Brake flush... Really??
