Purple Brake Fluid?

[Michel73]

I was out checking fluid levels yesterday and when I poped the top on the master cylinder the brake fluid is a transparent purple color What kind of brake fluid is this :confused


Save the Wave

 

[silver 80]

sounds like the old military silicon brake fluid.

 

[silver 80]

I forgot to say don't mix the two types of brake fluid.

 

[Stallion]

Is silicon the best fluid to go with? I should change that very soon.

 

[JonM]

I don't know what it is...but it sounds RICE to me...

 

[pws69]

I was out checking fluid levels yesterday and when I poped the top on the master cylinder the brake fluid is a transparent purple color What kind of brake fluid is this :confused

Save the Wave

My DOT 5 Silicone (new last yesr) is "a transparent purple color"

 

[Stallion]

So silicone is the best to go with then?

 

[pws69]

So silicone is the best to go with then?

I DEFINATELY think so - only exception is Racing. I have been VERY happy with mine.

 

[Stallion]

Okay, I think this is what I'll go with. But just out of curiosity, why is silicone no good for racing? What's the idea behind that?

 

[pws69]

Okay, I think this is what I'll go with. But just out of curiosity, why is silicone no good for racing? What's the idea behind that?

I believe there may be a couple of points. One is pedal feel - silicone is "more compressable" than glycol, so the pedal "won't feel as hard". When I did mine, I had replaced all of the lines with S/S and used braided caliper hoses. Plenty hard enough pedal for me!! There may be something regarding heat, also, but I don't remember. I love it in mine, so all the claims don't mean squat - my [manual] brakes DEFINATELY stop very well.....

 

[MaineShark]

The only big advantage of silicone is that it won't absorb water, like glycol will.

If you don't drive often (ie, the car sits for long periods of time), this can be an advantage.

In normal use, glycol is better. It is "stiffer," as pws69 says, and you won't have compatibility problems. If you don't completely flush all of your existing fluid out before adding silicone, the two will turn to glue wherever they mix.

So, if you really want to switch to silicone, you need to not only drain the system, but flush it with a flushing solvent.

I would say that there isn't much difference between the two, but the hassle of switching makes it easier and safer to stick with standard fluid.

Plus, if you ever need to top off the fluid somewhere, and there isn't silicone available (many places don't carry it), you're stuck.

Joe

 

[JohnZ]

Stick with glycol fluid - Castrol LMA (Low Moisture Absorption) is excellent, exceeds DOT4 specs, and is cheap. Most road-racers don't use silicone fluid due to its aeration problems and minimal boiling point advantage over glycol fluid - they use expensive synthetic fluids like Motul 600, which has a much higher boiling point, and flush/bleed it after every track outing (heat oxidizes it).

 

[froggy47]

Could be ATE BLUE (a very good dot 3/4 fluid I use). It comes in blue & amber so when you flush you switch the color & can tell when a complete flush is done