DOT-4 brake fluid?

[garcia]

Can you just purge the original (DOT-3) brake fluid and add DOT-4?
WITHOUT dissasembling and cleaning all brake parts?

[Nates'90]

Dont bother draining for fear of containation... Drain because it's allready contaminated. Dot 5 is where you need to worry about that.

It's fine to just dump in, but if you're low, check your brakes out (takes an hour if your lazy...)

If the pads are worn down really far, the caliper's gotta travel further to make it stop, and that uses more fluid. Same deal in the rear, except with the drums. Check for leaks also ;p That fluid is going somewhere, and it aint good...


~Nate

[jtgh]

3 and 4 and 5.1 but never 5. (more and link)
but first state , year,

the fuilds need to be compatible with each other, and with the rubber like seals.
many cars state , flat out , no 5.0 Dot fluids are to be used.
always contact the dealer on that, as this might change or they might find a new type that works.

I just use dot 4. it is very good. I remove it each year,
too bad 5.1 wasnt called 4.1.

so you an used 5.1 as it mixes in all proportions with dot 3 or 4. and never 5.
my sentenance shows the confusion.

here is a got wright up from some one with credentials.
Tech Tip: Brake fluid debate

i always try not to mix my chemistries, as this gets me in to trouble.
id run a full quart thru of the new fluid. (safe than sorry))

[Shconer]

DOT 4 is fully backwards compatible with DOT3. DOT 5 is silicone based and is for hi heat racing applications. DOT 5.1 should be compatible but I wouldn't bother as the DOT4 is good enough. Remember to put the cap back on sooner rather than later on anything containing brake fluid as it readily absorbs moister.

[jtgh]

that is very concise and accurate