Brake fluid

[BlackGTO]

With all the types out there now what are you alls opinions and preferances for drag racing. 3,4 and 5.1 I know only diff is boiling point with 5 being synth and more compressible when hot.

[TheSilverBuick]

I just filled up with DOT3 yesterday. For drag racing I'm not sure how hot the fluid gets, at least compared to circle track or autocrossing.

[BlueCuda340]

I think one benefit of the synthetic is that it doesn't eat paint. That being said my dads brakes(strange) recommends not to run dot 5?

I have always run dot3.

[Hemi Joel]

DOT 5 is the only way to go. I have been using it for over 30 years without one single problem. I first put it in my 67 442 back in 1980, drove it till 87, stored it for another 23 years, then drove it 5000 miles on Power Tour without touching the brake system except for adjusting. There is NO WAY that would happen with any othe type of fluid. Any fluid that can last 30 years without changing it and without some kind of failure is magic.

I also use it drag racing. The Wilwood calipers came with a tag that said "don't use DOT 5". BS, I use it any way, I have used it in Wilwood aluminum calipes for 10 years with nothing but excellent results.

[Bob Holmes]

Are you talking about 5 or 5.1. 5 shouldn't be used for anything except cars that sit for a long period of time. 5.1 is perfectly acceptable for just about anything.

Here's a nice Summary.

http://www.superchevy.com/technical/chassis/brakes/0509sc_fluid/index.html

[CDMBill]

I've been using DOT 4 for along time maybe time to consider 5.1?

[Bob Holmes]

4 is fine Bill. We use a high boiling point Dot 4 in the roadrace car, which will see braking temps for prolonged intervals that are much higher than you'll see in daily driving or drag racing.

I just picked up the latest Car Craft. There is a nice write up by Jeff Smith discussing the differences.