Brake fluid is possibly the single most neglected component of the automobile. Most high performance drivers check their tire pressures and change their engine oil at frequent intervals. Virtually no one (including me) ever changes the brake fluid in their street car - or even bleeds the brakes. WRONG!

The function of brake fluid is to provide an incompressible medium to transmit the driver’s foot pressure on the brake pedal through the master cylinder(s) to the calipers in order to clamp the friction material against the discs. The foot pressure is multiplied by the mechanical pedal ratio and the hydraulic ratio of the master cylinders, booster (if used) and caliper piston(s).

This is a simple concept. When fresh, all brake fluids are virtually incompressible and the system works as well as its mechanical and hydraulic design allows. There are, however significant problems. Overheated brake fluid can (and will) boil in the caliper. Boiling produces gas bubbles within any boiling fluid. Gas is compressible so boiling brake fluid leads to a “soft” brake pedal with long travel. In extreme cases overheated brake fluid necessitates “pumping the brake pedal” in order to get a pedal at all.

There are five possible solutions to the boiling fluid problem:

1. Don’t use the brakes so hard
2. Provide (copious) cooling air to the brakes
3. Install Titanium or Ceramic caliper pistons. Alternately install 2-piece pistons made from aluminum with a noise piece of Titanium or Ceramic. (Note that aluminum pistons are used as opposed to stainless steel to match the expansion rate of the piston to that of the caliper body to ensure the piston seal condition and preload is optimal through out the temperature range.)
4. Install Titanium pad backing plate if they are available for your caliper.
5. Change to a brake fluid with a higher boiling point.

I RECCOMEND INSTALLING CERAMIC BRAKE PADS. BETTER STOPPING AND LESS DUST...

The first is unlikly for the aggressive driver. You have to use the brakes to stop. The second one gets very pricey. The third is VERYYYY expensive in different forms. The fourth and Fifth are your best bets. The fifth one is MADNATORY DUH!!!

I reccomend these brands:


· AP 550
· AP 600
· ATE Super Blue Racing
· ATE TYP 200
· ELF HTX 115
· Motul 550
· Performance Friction Z rated

Castrol SRF IS THE BEST on the market due to its chemistry compounds. I highly reccomend it but its expensive.


This leads to a discussion of boiling points. Brake fluids are classified by both “dry boiling point” and “wet boiling point”. They are also classified by US Department of Transportation (DOT) rating, DOT 3, DOT 4, DOT 5, and DOT 5.1.

As we would expect the dry boiling point is just that - the temperature at which a given brake fluid boil when it is fresh out of the can. This is the rating by which most high performance drivers and all racers select their brake fluid – from the standard racing 550 degrees Fahrenheit to the 600+ degrees Fahrenheit offered by the extreme use fluids. As a point of interest, even though they may have the same DOT rating, racing fluids are less compressible than street fluids, especially after they have been overheated.

For high performance street car use, the wet boiling point is at least as important as the dry. DOT 3 DOT 4, and DOT 5.1 brake fluids are ether based and, as such they are hygroscopic in nature - i.e. they adsorb water at every opportunity. Since water boils at 212 degrees Fahrenheit (100 degrees Celsius) the adsorbed water dramatically lowers the boiling point of the brake fluid. A minute amount of water suspended in the fluid decreases the boiling point as much as 1/3. Damn!

The fluid in the system absorbs water through the breathers, through the caliper piston seals. Not only does this reduce the boiling point, the entrained water leads to corrosion of Aluminum internal parts. So buy your brake fluid in small containers. DO NOT SAVE LEFTOVERS. It will loose its compounds and not be as effective.

Basically what I am telling you. Keep good brake pads on your car with good rotors. Keep check on your calipers and there parts(MAINLY PISTIONS) Change your fluid regulary, use a high boiling point fluid, keep brake lines in check, and just dont slam on brakes everytime. FYI using gentler brakes SAVES GAS. When we hit the brakes we are using energy in the form of heat which is still using gas. Also if your going to be at a light awhile and your in a automatic, pop it in neutral. It will keep the transmission from fighting against itself.

 

Great thread; I have used ceramic pads in the past on previous rods with great results. I highly recommend them.

 

Some people say that Ceramic are not as powerful as regular ones and say 20 dollar pads are the same as heavy duty ones. I have to disagree. It all depends on the materials used. I also reccomend ceramic. They are proven to stop faster, VERY LITTLE BRAKE DUST.....which IMO, is a ***** to clean all the time off the rims. Ugh. Then again im lazy.

 

Mmm, yeh, I'm totally with you there. We're going ceramic for sure next set of pads. They were seriously amazing in how they kept the brake dust down to almost nothing, really.

 

btw for anybody that has ever heard that dot 4 brake fluid is higher performance. You heard right but dont DONT put it in your corvette. Some idiot brought his vette into the dealership with brake problems, he had used dot 4 brake fluid thinking it would make his brakes more responsive. Turns out he had to end up paying for new brake lines haha. idiot.

 

If he had read the top on the master cylinder cap DOT 3 BRAKE FLUID ONLY!!! Manufactors dont put those rules there for there health. What they say do, is only for your benefit.