I am going to be flushing the brake system in the near future and am wondering about dot5's compatibility with the Coopers brake system. I understand that DOT4 and Dot5 do not mix and the system will have to be THOROUGHLY flushed. Has any one had DOT5 in for an extended period of time and have there been any issues?

 

DOT 5 is silicone fluid. Don't use it! It doesn't absorb water, but it has a spongy feel. The water that does get in settles to the bottom of the system, causing corroded calipers. The one good thing is if spilled on paint it won't remove it. I had a vintage MG that I used that fluid in. It was just OK for that car, not for your MINI.

Here's some reading for you....

http://www.motorcycleproject.com/mot...rakefluid.html

http://www.xs11.com/tips/maintenance/maint1.shtml

http://www.babcox.com/editorial/bf/bf40142.htm

 

How often should DOT 5 be changed...can you go back to DOT 4?

 

There is also the DOT 5.1
This one is compatible with DOT 3 and DOT 4

The only one not compatible with any brake fluid is the DOT 5, stay away from it.

Victor

 

So you would recommend dot 3, 4 or 5.1?

 

IMHO? Motul RBF 600, Ate Blue or Ate Typ 200 are all good choices for fast street, AX, and track work... (and DOT 4) We've used all of them and will keep on doin' so.

For a cheap, locally available fluid that seems to work quite well for fast street and AX, Valvoline SynPower...

 

is Ate Blue okay for daily driving? bumper-to-bumper traffic? Just curious cause I've purchased some to go with my brake pad & rotor change.

 

I use ATe Blue and I like it a lot.

 

ATE Super Blue is great. It's in my 911 and my sportbike. The sportbike can really eat up brake fluid. The stock stuff went from clear to dark coffee color in less than 1000 street miles. I've had ATE Super Blue in it for 50k+ hard miles and only changed it once. No fade, no issues.

 

I just swapped from oem to super blue. I love it. Super easy to blead because of the color change and it has a great feel. Little to know fade since the swap... granted i switched to a bbk as well but the pedal feels great.

 

Yup!

 

While Ate is great stuff, we've boiled it before... Actually, I think we've boiled every fluid at one point or another here in Texas (and SoCal for Dr. Mike) with various combinations of brake setups and pads. Ducts helped a lot to alleviate boiling, but then Dr. Mike still managed to kill other BBK components.

Dr. Mike is way hard on brake components, hence the need for 11.75 x 1.25" rotors in the new BBK so Dr. Mike doesn't run out of brakes at the track. That's a bad, bad thing...

 

As an FYI, DOT 5.1 has also been referred to as DOT Super 4. I dunno why, but just check the dry and wet boiling points and you'll end up with the good stuff.

I used silicon once...

 

word!

3, 4 and 5.1 all are miscable (can be mixed). Check out the wet and dry boiling points. and choose based on cost and other factors.

If you're gonna do 5, hope it's for a race car where you bleed every track event (from both above and below). If you don't that water will pool in the bottom of the caliper and boil long before the fluid actually does.

FWIW, all those like ATE Super Blue and Motul 600 are Dot 4s....

Matt

 

wow i didn;t start this thread but thanks for all the info!

 

I like using the ATE Blue and Type 200. I bleed often since I do a lot of track days and by swapping from one to the other I can see by a color change when the system is fully changed.

 

Woah...ATE Super Blue is DOT 4...I knew nothing of brake fluid when I got the stuff. It was recomended and then was missclassified on some website. I don't know why I thought it was DOT 5. I'm glad it truly is DOT4 after reading up on DOT 5.

If anyone wants to poke fun at me go ahead.

 

If I seen knowledgable, it's just cause I've made more mistakes than most!

But one has to start somewhere....

Matt

ps, the best Confusous quote I know... "The only thing a truely wise man knows is the depth of his ignorance!"

I'm very, very wise!

 

Yes, ATE Super Blue is DOT 4 and good for the MINI, I've used it for 3 years now. No need for DOT 5 fluid.

Don't spill any brake fluid on your paint- it's bad.

 

all but 5 are water soluble, so just hose everything off after you're done!

Matt

 

Yes water soluble, but you had better move fast if you get any on the paint!!!

We are lucky with our MINI's. When the bonnet's up there's not much paint around to spill on.

 

It all depends on what you want. Dot5 people say should be replaced often but it should have great feel for the brakes.

Anyways I used to use the valvoline brake fluid which is pretty good for most tracks but then I went to willow springs horse thief mile. That was killer for my brakes. In fact after about 3 runs I pulled off the track and my brake peddal sunk straight to the floor. I totally thought that I broke the brake system, but it was the brake fluid boiling. Now I use a brand named NEO racing oil. Its very good stuff. I definately recomend it but definately dont expect everyone to use it. But it holds the record for the highest boiling temps of all other brands..