Are my brakes screwed?

Ok one day, I decided to drive fast on the open road, like 150k's, and then I had to quickly hit the brakes for the stop sign, cuz I know how much my brakes could take (I haven't even hit their limits yet, till now of course), so as I slow down to 30k, the brakes didn't feel like they were stopping anymore, so I floor the brakes to finish it. It barely slowed down!!!

So I turn right and no one was around so I tried to skid my tires, but no matter what I did, I couldn't!! There was a mushy pedal feel (I think it's the air bubbles in the lines), so I turn into a gas station to let it cool down, when I stopped the car, the brakes were SMOOOKING!! I turn off the car for 5 mins and when I got back to driving, the brakes were better, but not as good as they were before (Still got a bit of the mushy pedal feeling). I am thinking of flushing out the fluid and putting in DOT4 fluid instead, but the cap says "dot 3 fluid" only, so what do I do? I don't even trust my brakes that much anymore.

Because you where at such a high rate of speed and slamed on the breaks the heat bulid up probley glazed the surface of your breaks which lowered there stoping ability, and if they did get hot enough then the fluid inside the calipers probley boiled creating air bubbles and mabey i don't know messed up the fluid.

Use some break cleaner, and do a couple highway speed stops by pumping the breaks to get some glazing off.

If your breaks are pulsing during normal stops you probley warped your roters, mabey.

if u wanna pull little stunts like that next time have vented and slotted discs and the calipers to support it!

Because you where at such a high rate of speed and slamed on the breaks the heat bulid up probley glazed the surface of your breaks which lowered there stoping ability, and if they did get hot enough then the fluid inside the calipers probley boiled creating air bubbles and mabey i don't know messed up the fluid.

Use some break cleaner, and do a couple highway speed stops by pumping the breaks to get some glazing off.

If your breaks are pulsing during normal stops you probley warped your roters, mabey.

Pads glaze when they are overheated and the organic particles in your pads melt and boil to the surface of the pads. (this would be some of the smoke you saw) It then cools and solidifies forming a nice glossy coating.

A more effective way to remove the glaze is to remove them and sand them down a little. Its only the topmost part that has become glazed. Brake cleaner removes grease, not glaze.
Better yet, change your pads and machine the rotors.. If you do this stunt again, use metallic pads, not cheapo ones. Try this approach BEFORE changing your fluid, and you will restore your brake performance.

"if u wanna pull little stunts like that next time have vented and slotted discs and the calipers to support it!"

I DO have vented discs, not slotted though :(


Pads glaze when they are overheated and the organic particles in your pads melt and boil to the surface of the pads. (this would be some of the smoke you saw) It then cools and solidifies forming a nice glossy coating.

A more effective way to remove the glaze is to remove them and sand them down a little. Its only the topmost part that has become glazed. Brake cleaner removes grease, not glaze.
Better yet, change your pads and machine the rotors.. If you do this stunt again, use metallic pads, not cheapo ones. Try this approach BEFORE changing your fluid, and you will restore your brake performance.

Thanks, now I understand it all. Would changing brake fluid help as well? My teacher doesn't think brake fluid is that important (he hasn't changed the fluid in his car for 20 years haha), but I guess he doesn't understand why...

"if u wanna pull little stunts like that next time have vented and slotted discs and the calipers to support it!"

I DO have vented discs, not slotted though :(


Thanks, now I understand it all. Would changing brake fluid help as well? My teacher doesn't think brake fluid is that important (he hasn't changed the fluid in his car for 20 years haha), but I guess he doesn't understand why...

Aren't most breaks nowadays vented?? I'm pretty sure on all cars discs are vented, but motorcycles it's just like .25 inch thick metal or somethin. But spend a little money and get better rotors/pads, lines, etc. Brakes are VERY i'mportant.

There are a few solid rotors, I believe that they are often the rear rotors on four wheel disc brake vehicles. A prime example would be the rear rotors on many Integra's.

"if u wanna pull little stunts like that next time have vented and slotted discs and the calipers to support it!"

I DO have vented discs, not slotted though :(


Thanks, now I understand it all. Would changing brake fluid help as well? My teacher doesn't think brake fluid is that important (he hasn't changed the fluid in his car for 20 years haha), but I guess he doesn't understand why...

It sounds that your teacher don't know much about brake fluids. The fluid should be replaced, about once every second year if I remember correctly.
The brake fluid will get contaminated with water which cause the system to corrode and it also lowering the boiling point for the fluid.

When braking hard like this the pad material, brake fluid and brake mass is what is important, not the cooling of the brakes as this is supposed to cool the brakes between braking.

Also, if the brakes gets really hot, drive for a while without using them and they will cool down faster than if the car stands still.

The glazed surface on the pads will wear off and the brakes should go back to normal.

There are racing brake fluids availible which can tolerate higher temperatures than normal fluids, for example:
http://www.motul.com/uk/produits/index.html
[racing - car - brake fluid]

It sounds that your teacher don't know much about brake fluids. The fluid should be replaced, about once every second year if I remember correctly.
The brake fluid will get contaminated with water which cause the system to corrode and it also lowering the boiling point for the fluid.


The only exception to this rule is DOT 5 fluid, which is silicone based, not glycol based like regular fluid.
Regular fluid is hydrophilic, which means that is attracts moisture from the air. This is why one must be sure the master cyl in a car is properly sealed. However, whenever you open the master cyl resivoir to add fluid or check the level, moisture is introduced into the system.

DOT 5 fluid is the only one that can be left in a brake system without risk of water attraction. However, it is not compatible with regular fluid - a change over requires flushing the system with alcohol - and bleeding air from a system with DOT 5 is troublesome, since the fluid itself is thicker than the regular stuff.

Don't confuse vented with slotted or drilled. Vented is the sandwich style, where there is a rotor surface inside and out, separated by ribs in the middle. It is vented since the air can pass in between and cool it. Slotted and cross drilled mean just what they sound like. Both slots and drilled holes allow for expansion outgassing to escape from the friction surface. Non-slotted or non-drilled rotors under hard braking create more outgassing than can escape, and effective friction can be decreased from the small pocket of gas between the pad and rotor. Make NO mistake. A slotted or cross drilled rotor (all other factors the same) will make MORE heat than a flat rotor. The whole point is that it makes more friction by letting the gas out. More friction means more heat. There is no way of getting around this. The minute amount of heat that the holes let escape is much less than the friction it creates. Heat is what glazes pads, so proper choice of pads with these rotors is key. In this person's case, just switching to slotted/drilled rotors and keeping the same pads will make the problem worse. There is no magic here. Metallic pads take the heat better, but eat rotors. Organic pads won't take the heat, but are easy on rotors. So far the best compromise is ceramic pads. They take heat almost as well as metallics and stop about the same as organics without the fade associated with glazing.

DOT5 fluid is not just incompatible with other brake fluids, it is not compatible with most brake components. It eats rubber for lunch and will corrode otherwise normal brake parts. Do NOT use it unless your parts are specified for DOT5 silicone fluid.

Flushing your system regularly will eliminate bubbling problems. Careful selection of pad and rotor composition will eliminate the fade problem.