Brake Fluid Identification ?

[Racer57]

Is there a way to identify what kind of brake fluid you already have in the car ?

[Chryco Psycho]

Yes if you take a small amount & add water , DOT 3 & 4 will mix , alcohol based , DOT 5 is silicon based & will not mix  .
I always use DOT 5 in cars I rebuild as it will not affect paint , use DOT 4 over DOT 3 if you are using either as DOT 4 has a higher boiling point .

[Racer57]

Yes if you take a small amount & add water , DOT 3 & 4 will mix , alcohol based , DOT 5 is silicon based & will not mix  .
I always use DOT 5 in cars I rebuild as it will not affect paint , use DOT 4 over DOT 3 if you are using either as DOT 4 has a higher boiling point .

Thank you !!   Thats one of those common sense answers that makes a person think "Why didn't I think of that !! "