I believe the manual says to replace brake fluid every 2 years. My other German cars say the same. They claim it is because the fluid is "hygroscopic" (I think that's what it is anyway). I understand the logic.


But really?? Other car manufacturers don't all have this same requirement.


What's up with this? It looks to me like the Porsche dealership has a great angle to get you to bring the car in for service. And it aint cheap.


Any comments on this? Anybody ever had trouble because they did not follow the 2 year cycle?

 

My 02 Boxster's clutch action got jerky, that is it was hard to take off from a stop with no judder. Shifting was not as smooth as it was. Transmission fluid was ok just changed within the last 12 months.

The clutch was smooth before. I pride myself on my smoothness with the clutch and clutch life I think bears out how smooth I am: 278K miles on the original clutch.

Anyhow, talking to my service manager and on a hunch had him look up when I last had the brake/clutch fluid flushed/bled. Around 2.5 years ago is what he found from the service records.

Booked the car in for this service and afterwards the clutch was once again smooth and the shifting back to its previous hot knife through butter smooth.

Braking action as near as I could tell was unaffected. It was ok before. But I imagine the braking system is better off with the old fluid gone and replaced with new fluid.

Up to you but frankly I think you're crazy to let this go just because other automakers seem to think it is not a concern. Maybe they'd rather hit the jackpot and do a brake system rebuild rather than a nickel/dime piddling fluid service?

For the price of a fluid service, I could have instead gone through a clutch or even a tranny. A lot cheaper to have the fluid service done that replace a clutch or have the transmission rebuilt.

Besides, I do not think it is that much money. And you can consider doing it yourself. I've done it myself in the past.

 

It's cheap insurance - especially if you happen to be hard on your brakes. It's a must do if you track your car. ie once the fluid heats up along with the water that in the system...brake pedal will be very soft or possibly to the floor....ask me how I know!

 

I change mine much more than every two years, but I track my car. Brake fluid absorbs water(hydroscopic), which reduces the boiling point of the fluid. If you've ever boiled your brake fluid, you'll know its not a good situation to be in. If you are mechanically inclined, buy a power bleeder for about eighty dollars and do it yourself. All you need beside the bleeder is a floor jack, jack stand and flare nut wrench for bleeder. The first time might take a couple hours, but I can do mine in about 30-40 minutes. I use ATE super blue and gold, and switch colors every time I flush so I know when I'm getting fresh fluid out of the caliper.

 

its 2 years for other car makers too.

motul rbf600 and rbf660 are the best fluids around without spending big bucks. it's better than ATE which i also use. motul has higher pointing points though

 

Macster, I am not up to speed on the Boxster. But your post implies that the clutch system and the brake system share hydraulic fluid. I definitely can imagine a change of fluid could help the clutch in that case.


But for my 911 Turbo S the clutch system is different. It shares fluid with the "assisted" steering system. That way it uses the steering system pump to pressure the clutch and make the clutch easier to depress.


That leaves the brake hydraulic system isolated from everything else. Hence my question on service intervals.


In any case, your clutch has lasted forever! I only wish I could get that many miles on my clutch.

 

There is a wide variety of requirements for brake fluid changes depending on which vehicle one owns.


I know that MB requires 2 year changes. Porsche, too. But for example:


Subaru 30k miles, no time limit
Chevrolet 150k miles
Ford, Chrysler, Toyota don't even mention it in their service requirements


I suppose it is possible that different system designs demand different requirements. But they all use a similar type of brake fluid.


So the question: Why are there widely different service requirements?

 

I flush mine with 1.5 liters of new fluid at the beginning of the season and then bleed the calipers every 6 track days or 2 months whichever comes first. I use Endless RF650. Factory Cup car fill. Takes 1hr to do. Very easy with Motive. For a street car the 2 year interval is fine. Pretty much industry standard for German cars which are subject to Autobahn speeds. I have boiled Motul 600 that was less than a year old. Not a pleasant experience. Only has to happen once to learn your lesson...

 

"I suppose it is possible that different system designs demand different requirements."

I'll say - I would bet there aren't many Ford Escorts that track regularly at 150+ MPH for a few hours on the weekend and go to work the Monday like nothing happened. I makes sense to me why Porsche has a different schedule...

 

The fact is, if you go beyond 3 years, you can hear the system making noises when braking slowly and you definitely can lose brakes altogether when you have repeat hard braking. It happened to me in the 80s on my first car. Trust me, you don't want to lose brake at 70mph coming down an incline!

 

Those are valid points.


But the Chevy Corvette is a quite capable car that can be tracked. Chevy, nevertheless, still does not push the brake fluid replacement. Please no flaming the Corvette. I think it is a real car! Especially the new model.


That said, if I was tracking a car (any car) I would definitely replace the brake fluid. Probably more frequently than 2 years.


But here is my dilemma: I only drive the Porsche on weekends. I bet it only gets 1500 miles per year. As a note, the car is almost 10 years old and it only has 17k miles on it. The brake fluid has been changed--I think about 4 years ago.


So no hard tracking. It's whole life is in a warm garage. Not in the rain. Etc. etc.


Cost is not the issue. I am just trying to rationalize the different specifications.

 

It is over due! I hv two cars that see about 2-3k miles a year. Both changed at 2-3 yr intervals max. Your life may depend on it. It's easy to do yourself too if convenience is a factor. Changing brake fluid is actually more important than differential and trans fluids, which is not time dependent. Yet, any exotics do trans and diff fluid annually. That's a waste of time and resources

 

Unless you track the car why change it? Don't get caught up in the maintenance schedule. Do what makes sense. My 2 cents...

 

Well, there are many opinions on this, I guess.


I can convince myself to change it and then convince myself to not change it.


I have too many back problems to be able to change it myself, so it means a run to a shop at some point.


Currently, the car stops perfectly and has no symptoms of an issues at all.


I suppose I will continue to drive for a while and then have it changed this summer sometime.


Thanks for all of the feedback. If anyone else has any more comments, please add on.

 

If your car is a garage queen, I see no need to follow the maintenance interval to the same degree. The published maintenance schedule has been developed to allow the car to perform optimally for the purpose for which it was designed. No one would argue here that if you track it every day, you would change the fluid more frequently. It naturally follows that if you don't drive the car, change intervals could be extended as well.