Rodney

tried the search, but to no avail..

dot 5 silicone brake fluid anyone? i'm overdue for a fluid flush, and was thinking about dot 5 silicone. i know it has a higher boiling point, but what about it's resistance to water absorbtion? do you have to bleed it more often? i need some real world experience here. i have spoke to a variety of people, and everyone has a wildlt different opinion? anyone care to take a stab at it? thanks.

Grumpy

Most raceers don't use it. There must be a reason.

Mine was that I could never bleed out all of the microscopic bubbles in the fluid and always had a soft pedal.

Grumpy

typer_801

DOT 5 = no, no (has silicone, will ruin your whole system) unless your system is designed and already has DOT 5 in it.
DOT 5.1 will work well, but expensive.

Why not just used a good DOT 3/4 fluid. ATE Super Blue/Type 200 are more than adequate for most cars and is $10 a liter.

Here's a nice link with comparisons of BP's between many fluids. It comes to the same conclusion. Choice is your's however...

http://www57.pair.com/lane/bfluid.htm

nsxtcjr

Another bad thing about DOT 5 (silicone based brake fluid) is that you can't mix DOT 5 fluid with non-silicone based brake fluid, like DOT 3 or DOT 4 or DOT 5.1.

No, it isn't.

Better yet, why not get a fluid that has even higher boiling points than ATE, like Motul RBF 600? It costs about the same as ATE.

Here are the dry and wet boiling points for many of the most popular brake fluids:

ARRANGED BY DRY BOILING POINT:

DRY:401F -- WET:284F --- DOT3 MINIMUM
DRY:446F -- WET:311F --- DOT4 MINIMUM
DRY:500F -- WET:356F --- DOT5 MINIMUM
DRY:502F -- WET:343F --- VALVOLINE SYNPOWER
DRY:509F -- WET:365F --- MOTUL 5.1
DRY:527F -- WET:302F --- AP RACING 551
DRY:536F -- WET:392F --- ATE SUPERBLUE/TYP200
DRY:590F -- WET:410F --- AP RACING 600
DRY:590F -- WET:518F --- CASTROL SRF
DRY:593F -- WET:420F --- MOTUL RBF600
DRY:610F -- WET:421F --- NEO-SYNTHETIC SUPER DOT 610


ARRANGED BY WET BOILING POINT:

DRY:401F -- WET:284F --- DOT3 MINIMUM
DRY:527F -- WET:302F --- AP RACING 551
DRY:446F -- WET:311F --- DOT4 MINIMUM
DRY:502F -- WET:343F --- VALVOLINE SYNPOWER
DRY:500F -- WET:356F --- DOT5 MINIMUM
DRY:509F -- WET:365F --- MOTUL 5.1
DRY:536F -- WET:392F --- ATE SUPERBLUE/TYP200
DRY:590F -- WET:410F --- AP RACING 600
DRY:593F -- WET:420F --- MOTUL RBF600
DRY:610F -- WET:421F --- NEO-SYNTHETIC SUPER DOT 610
DRY:590F -- WET:518F --- CASTROL SRF

typer_801

HUH?!? Unless my math skills have seriously deteriorated, Motul RBF is more than twice what ATE costs.

Motul RBF shows up at $12.99 per 500ml (1/2 liter) at Racer Parts Wholesale, while ATE SuperBlue can be had at OG Racing and many other places for $10/liter or around $5/500ml. It's much more expensive if you ask me!

Warren

I prefer Motul. If you call around to local bike shops, you can pick it up for $10 each. I dunno why it's more expensive online. Kind of odd.

Yeah, it's twice as much as ATE, but I have had 2 problems with ATE. First, is that sometimes it eats seals, especially in Audis (odd since Audi uses an ATE master cylinder), and second is that ATE has a squishy pedal by the end of one day.

Warren

4doorH22

Anyone know if ATE eats seals on Hondas? I've been using ATE for quite some time with zero problems. Pedal is only begining to get mushy now after 5 months and 3 HPDE weekends since the last flush. Then again I don't drive like Warren... but my car does weigh more and has smaller brakes...

Crazydave

Just run motul and be done with it

typer_801

No problems ever here <knock on wood> Been using ATE since the early 90's in a variety of cars (4 VW's and the Type R).

For a street driven car that sees occasional light track or autocross action ATE is more than adequate. For a more dedicated race setup, I'd probably go with a higher performance fluid like the Motul, but it's not necessary for me.

nsxtcjr

You might be right - although you can get Motul for less elsewhere, say $10 for a half liter. That means every time you do a full flush of your fluid, it will cost you $10 more ($20 vs $10). Maybe you flush once a year, maybe twice a year. So for an extra $10, maybe $20 a year, you get boilover protection that's 57 degrees F higher. That's a HUGE difference in the boiling point - and well worth spending a few bucks more a year.

I have yet to understand why people will try to skimp out on brake fluid for a few bucks, and risk fade and boilover at the track. You probably get more value for those few bucks by spending them on brake fluid than on any other mod on your car.