dot 5 silicone brake fluid?

[patriot68]

can i use dot 5 brake fluid in my 68 camaro for brakes and clutch?. my brake and clutch systems are completely new..calipers/lines/master/slave....i would hate to ruin my paint if regular brake fluid spilled on it. thanks
scott

[1sick65]

I have been running it in my car for two years with no problem. As long as you have no DOT3 in the system, you should be fine. Not sure about the clutch.

[patriot68]

cool. thanks

[Skip Fix]

Silicone fluid saved my paint job one time when I manually bled the system but forgot to put the MC cover back on! I've had no spongy pedal as some describe and have used the car for autocrossing and drag racing.

[parsonsj]

I'm surprised ... I did a lot of research and found *nobody* recommending DOT 5 fluid in anything other than a show car.

No worries, huh?

jp

[ahowudoin]

I work on alot of postal trucks and they all have dot 5.We don't see many calipers or wheel cyls. leaking either for the amount of brakes they go thru.

[Joe_Rocket]

I've been running DOT 5 in my 69 Camaro for a couple years. i made the switch after not realizing the new chrome bar that holds the new chrome master cylinder cover on wasn't snug enough and the fluid splashed over the top on acceleration and ate all the fresh painted components in the engine compartment.

My search on the subject which that since water is not absorbed by silicone, you have two problems which I think are the most critical.
1) Corrosion, which may not be much concern (compared to stock components) in a stainless system with aluminum master and aluminum calipers. Anyhow, I found warnings of potential for pinhole leaks from a drop of water corroding it's way through some point in the system.
2) The water works it's way to the lower points in the system where under heat turns to steam and loss of breaking power.

Obviously, in the non-silcone brake fluids water in the system will lower the boiling point and cause problems, too. So, periodic bleeding is necessary no matter what you run. But since water is absorbed into the brake fluid, the drop in boiling point is not as drastic as having a drop of non absorbed water boiling at a much lower temperature.

But with silicone brake fluid, there are a couple other issues. Air bubbles don't seam to work their way to the top as easily and I find it impossible to bleed without a power bleeder. Also, I can't help but wonder how easy it would be to push out any droplets of water that may have settled in the calipers when bleeding considering the exit is at the top.

That said, I've run it for a while with no ill effects, though i haven't driven very hard on them. I'm usually upgrading and evloving the car more than I atually dirve it. :P

[Skip Fix]

Mine has been in for almost 15 years, with a few bleeds when I replace that "nicely" designed TA factory ratchet calipers.

[Bandit]

I just received my Wilwood big brake kit, and it states specifically in the instructions to run Dot 5.

[parsonsj]

I just received my Wilwood big brake kit, and it states specifically in the instructions to run Dot 5.You sure? My Wilwood kit has the following instructions:

NOTE: Silicone DOT 5 fluid is NOT recommended.

Which kit are you using?

jp

[parsonsj]

From Wilwood's website:

Wilwood does not recommend using DOT 5 fluid in any racing applications. DOT 5 fluid is not hygroscopic, so as moisture enters the system, it is not absorbed by the fluid, and results in beads of moisture moving through the brake line, collecting in the calipers. It is not uncommon to have caliper temperatures exceed 200° F, and at 212° F, this collected moisture will boil causing vapor lock and system failure. Additionally, DOT 5 fluid is highly compressible due to aeration and foaming under normal braking conditions, providing a spongy brake feel. DOT 5 fluid is best suited for show car applications where its anti-corrosion and paint friendly characteristics are important.

[CarlC]

For a mild street application it might be fine, but for any type of performance environment a DOT3 or 4 should be used.

I believe David Pozzi has seen several cars wreck due to the DOT 5 fluid being used in a track environment.

How many performance oriented companies sell or use DOT 5?

[Bandit]

I made an erroneous statement earlier, Wilwood DOES NOT recommend DOT 5!! Rather, they call for their 570 or better, which is a high-temp DOT 3 fluid.
Sorry for the confusion.

-Paul

[BRIAN]

If you are using the 3 o4 4 stuff and worried about paint problem try: Spraying area with soap and water before you put fluid in system. Also keep the sprayer near by if it leaks. I read trick somewhere and it does work. I sprayed fluid all over a firewall that was freshly painted. I had the soapy solution on there and it wiped right off. Tense couple of minutes but it's better than resanding and spraying.

[Flyboy]

We use Motul DOT4 brake fluid in the short track stock cars at the shop I work at. Good stuff, but it comes in small bottle and is expensive. You can generally find it at any motorcycle shop that sells performance parts.