Dot 5 or Dot 3 brake fluid?

[resq302]

I have just heard of the Dot 5 brake fluid which supposedly does not ruin your paint if you should leak it somewhere.  How does Dot 5 compare to Dot 3?  Does it absorb moisture as well or will it cause problems in my new brake system?  I am replacing all of my brake lines and wheel cylinders so if I do the swap over on the fluid, now is the time.  I heard that the two are not compatible also.  Is this true?

Any info would be greatly appreciated.

thanks in advance,

Brian

[Plumcrazy]

Use DOT 5
Won't damage paint
Higher boiling point
Doesn't absorb moisture

[bad1032]

I would go with dot 4 , they are not compatible, Harley used dot 5 and has switched away from it, Its a silicone based fluid.

[resq302]

I was pretty sure that the Dot 3 and 4 were not compatable with the Dot 5.  The reason why I wanted to know is that I am totally replacing all of my brake components with the exception of the master cylinder which should be able to have the Dot 3 stuff flushed out.  My concern is the possibilities of leaks and ruining the paint job. 

Also, if it is silicone based, wouldn't that benefit the rubber parts and prevent wear?

Isn't Dot 4 just a newer version of Dot 3?

[Silver R/T]

go with Dot5, make sure theres no old dot 3 left in system and itll gel up if two are mixed

[1973_WP29P]

Standard old Dot3 lowest boiling point.

Dot 4 higher boiling point used in imports alot through the years.

Super Dot 4 used more for racing and put in VW's at the dealership.

Dot 5 all out racing highest boiling point, harder to find if low on fluid, costs alot, not many places stock it and some auto parts people have not heard of it.

I'd use Dot 4 or Super Dot 4.


                                                                                           Rod

[1973_WP29P]

Found this.    http://www.sdvsa.org/BrakeFluidFacts.htm



                                                                    Rod

[bull]

Use DOT 5
Won't damage paint
Higher boiling point
Doesn't absorb moisture

[hemi68charger]

Hey gang..
Going to bring this up again................. If I go from DOT 3/4 to 5, do I need to get every last drop of 3/4 out before the 5 can go in? I mean, I would think it's next to impossible to get every drop out.

Troy

[lisiecki1]

i think you have to flush the lines with alcohol to clear them out completely.....hard to do without a flush/fill machine....a decent auto shop should have such a machine and be able to do the fluid swap for you.