Brake fluid question
Thread Starter
Instructor
Joined: Sep 2001
Posts: 129
Likes: 1
From: North Central TENNESSEE
Brake fluid question
The brakes on my wife's 69 were replaced before we purchased the car last spring. The car needs a little brake fluid and I was wnodering how I can tell what to use. Is there a way to tell if it's DOT 3, 4 , or 5?
Thanks in advance for any help!
Alex
Thanks in advance for any help!
Alex
Burning Brakes
Joined: Nov 2005
Posts: 1,143
Likes: 0
From: Leander Texas
Originally Posted by Alex in Germany
The brakes on my wife's 69 were replaced before we purchased the car last spring. The car needs a little brake fluid and I was wnodering how I can tell what to use. Is there a way to tell if it's DOT 3, 4 , or 5?
Thanks in advance for any help!
Alex
Thanks in advance for any help!
Alex
Each type of brake fluid has a different boiling point. If you look in the master clyander, and the fluid looks rusty or redish colored it should be changed. (Brake fluid will degrade over time. If I remember correctly it is also an alcohole derivative which attracts water.) For most applications Dot #3 is fine. Silicone fluid (the purple Dot #5) can react with the seals in systems designed for Dot #3.
Team Owner
Joined: Jul 1999
Posts: 26,545
Likes: 46
From: Huntersville NC
changing completely is kind of a big job, especially if you are concerned about mixing silicone and regular. In that case you would want to clean out the brakelines with denatured alchohol to make sure there are no remnants of the old stuff remaining.
Far easier to test what is in there. Regular brake fluid eats paint. Silicon does not. I think most tests rely on that difference. Don't recommend putting a few drops on your hood, but that is the general idea.
Far easier to test what is in there. Regular brake fluid eats paint. Silicon does not. I think most tests rely on that difference. Don't recommend putting a few drops on your hood, but that is the general idea.
