break fluid what kind
7 Answers
What kind break fluid do I need
The brake fluid reservoir cap should say what type of fluid you need and the owners manual may also tell. It should be DOT 3 but double check that due to the brake fluid recall a few years ago.
That’s not on the reservoir or owners manual for my 2006 or 2010.
DOT 4 brake fluid is best. It is compatible with DOT 3. It is just like using synthetic motor oil which is better. 4 has a higher boiling point and does not absorb water like DOT 3 can.
Guru9RXX3N answered about a year ago
DOT 4 brake fluid has a higher boiling point than DOT 3 when new. However, it is MORE hygroscopic(absorbs water) than DOT 3, and therefore has a lower boiling point when it's a few years old. I learned that in my 15 years of working as a BMW tech. The German car makers all use DOT 4 but they emphasize that the entire brake system should be flushed out yearly. Some American owners actually did this, but most didn't bother because they'd never flushed the brake fluid on any of their American cars, which resulted in lots of leaking master cylinders, wheel cylinders and calipers, and hydraulic clutch cylinders on BMWs. If you aren't planning on flushing and replacing your brake fluid frequently you might be better off with DOT3.
