Change interval for brake fluid

[356robo]

My 70 911 only sees about 2500 miles a year of casual street driving. What is the recommended brake fluid change interval in years?

Thanks in advance,

Rob

[911quest]

15k or two years which ever comes first.

[docrodg]

As posted on pelican under this question... mileage is not the concern, it is exposure to water. Change it every 1-2 years with new fluid. If you open a bottle and don't use it all it is no good after some time (3 months max) due to water absorption.

[Bullethead]

+1 docrodg, brake fluids are hydrophilic, i.e., absorbing moisture even from the atmosphere. Flush and replace every 2 years minimum,
especially if you live in a humid location. Even if your brake lines are stainless.

High performance silicone brake fluids are even more hydrophilic and generally shouldn't be used in street applications.
A track car's brakes see duty that requires frequent servicing, including fluid flush/replacement.

[356robo]

Thanks for all the responses. I have to admit that its been 5 years. So, what should I look for related to the possible moisture issue? What fluid is recommended?

Thanks again to all,

Rob

[2.7backdate]

If the car sees ANY track duty, you are crazy to have brake fluid older than 6 months. Our PCA region insists that brake fluid be less than 6 months old to attend a DE or autocross event.

[ttweed]

Our PCA region insists that brake fluid be less than 6 months old to attend a DE or autocross event.

Being a former tech chair for our region, I am wondering how you "insist" on this requirement and if you actually enforce it somehow. Do you actually open every MC in tech and test the fluid for moisture or copper content?

Thx,
TT

[desertpagoda]

Hydrophilic? Close, HYGROSCOPIC. In Mercedes Benz school, a hundred years ago...were taught "every two years preferrably in the spring"

[Bullethead]

^^^ A fine distinction as both mean almost the same thing... but you're right, hydroscopic is more correct. My bad.