Brake Fluid

[Lee Patterson]

Any recommendations on DOT 4 vs. DOT 3 for a brand-new SPF brake system (which is all Wilwood). Wilwood specs their 570 fluid for street use which is actually DOT 3. I have used Pentosin Super DOT 4 in other cars with good results.

Input welcomed.

 

[Lee Patterson]

And to add confusion, Wilwood DOT 3 is now DOT 5.1 per what they are shipping. Backward compatible.

 

[Walter]

Castrol React Performance DOT4 (clutch and brakes for street car)
Castrol React SRF Racing DOT4 (brakes race car)

 

[DaveM]

For street use Prestone DOT 4 has worked fine for my SPF. When I used to track the car I used Wilwood 570.

 

[Bill Kearley]

Dot 5 for me, it won't absorb water from the air !

 

[Jerry Irwin]

Dot 5 for me, it won't absorb water from the air !

i used that ( dot 5 ) on my race car clutch centre release bearing and it dissolved the o ring rubbers !
dot 4 was fine..
Jerry

 

[Rick Muck- Mark IV]

Dot 5 for me, it won't absorb water from the air !

Bill,

Correct, it will not "absorb" water, but the system can still accumulate water. And the DOT 5 allows the water to sink to the low points and corrode parts. The reality of brake fluid is it needs to be flushed and changed every few years for best performance and corrosion protection. A few bucks worth of fluid, a friend to help and a couple of beers is a good invest in better braking and lifespan.

 

[Lee Patterson]

Wilwood does not use nor spec DOT 5 which is silcone-based. Has to be DOT 3, 4 or the new 5.1 which is glycol based. thanks for the input.

 

[Dale Murray]

Rick Muck is correct about DOT 5 fluid. It was in a used Lotus that I bought and the master cylinder was terribly corroded.
I stick with Motul 600 for my performance cars. It handles heat and it doesn’t damage paint if you spill it.

 

[Bill Kearley]

I'v never herd of Motul 600, If I flush with it, will the residue be compatible with DOT 3,4 or 5 ?

 

[Rick Muck- Mark IV]

I'v never herd of Motul 600, If I flush with it, will the residue be compatible with DOT 3,4 or 5 ?

When changing fluid type a really good flush is in order. Some like to use alcohol (A nice single malt is good) to flush and then leave the system open to dry. We have found a thorough flush with the new fluid type of one complete master reservoir is sufficient and then a full bleed with the new fluid type.

 

[Dale Murray]

Bill, Motul 600 has been popular for a long time, especially with motorcycles. It's cheaper than Castrol SRF which I've seen mentioned here, and as I said, it doesn't harm paint. Compatible with any other fluid.

Rick Muck's comment is spot on for changing fluid.

 

[Lee Patterson]

Since I started this thread, I will post what I found as a brake fluid comparison which is very detailed and lists lots of fluids. Depending on where you live, it's hard to find some of these. I am going to use the Wilwood 570 which is now a DOT 5.1 Glycol-based fluid (not to be confused with DOT 5 Silicone-based).

Brake Fluid Comparison Shopping

Resource guide of all (125 listed) high performance automotive and racing brake fluids. Boiling points, cost comparison, Google Shopping links, manufacturer links, additional helpful info.

www.lelandwest.com

 

[Dale Murray]

Lee, That's a great comparison chart. Clearly took a lot of work.
Thanks

 

[Bill Kearley]

Thanks for the help, Lots to work with !!