Endless Brake tip: Pad fade vs. vapor lock

17 Aug

I just realized that I never posted this here and it is already a month old. Oh well, I still would like to post it even though it is old news.

Brakes not working as they should in demanding conditions? Here’s an easy way to tell whether it’s a problem with the brake pads or the brake fluid.

Pay attention to what the brake pedal feels like when experiencing brake problems. Then ask yourself this simple question; is the brake pedal alarmingly soft and spongey, or is it really stiff and unresponsive?

A soft pedal most often indicates that your brake fluid is boiling, also known as ‘vapor lock.’ When your brake fluid reaches a high enough temperature and boils the fluid, air bubbles form inside your brake lines. Since air is far more compressible than liquid, brake fluid in this case, pressing the brake pedal with air in the lines results in a soft, spongey feeling. You can temporarily solve the problem by bleeding your brakes to get the air bubbles out, although you can expect the problem to reoccur if left alone. A high performance brake fluid like our S-Four or RF-650 will increase the amount of heat it is able to withstand, often preventing the problem of vapor lock entirely. Although often overlooked, brake fluid is an integral part of your cars braking system, as when it is not upgraded, it is most often the first component to reach its limits.

A hard, unresponsive pedal most often indicates that the temperatures are exceeding the limits of the particular brake pad compound, also known as ‘pad fade.’ Certain compounds are meant to handle different temperature ranges, with some materials being capable of withstanding higher temperatures than others. If you experience brake pad fade while driving, it’s a good idea to stop and let the brake pads cool. Endless brake pads have excellent fade recovery, meaning that should you reach the limit of a particular compound, let them cool down to their optimal operating temperature range and the pads will return to normal function. The key, however, is to choose the correct brake pad compound for the type of driving you intend to do. We, at Endless USA, are always more than happy to help you in making the appropriate selection according to your particular setup and preferences.

2 Responses to “Endless Brake tip: Pad fade vs. vapor lock”

  1. rlb August 17, 2009 at 6:58 AM #

    “If you experience brake pad fade while driving, it’s a good idea to stop and let the brake pads cool. ” is bad advice and sure to warp rotors. Nothing like keeping the area under that pad super hot while the rest of the rotor cools…makes a nice potato chip shaped rotor.

    Better idea? Keep driving…slower…then either upgrade your brakes or use them properly.

    Not long slow braking, but short hard braking. Rotors and pads are heat sinks. When you brake you are filling them with heat and when you are not braking they are shedding heat. Thats what bigger brakes are really about…more heat capacity.

    Once they are “full” of heat they stop working and bad things happen. Use long slow braking and you are filling up the heat sink to capacity and minimizing cooling time available. Use short hard braking and you expand the time available to shed heat.

    Try it …it works!

  2. Dom August 18, 2009 at 6:40 PM #

    Ouch. Struck down by a 110% literal interpretation.

    He’s definitely right. Don’t stop immediately and let the car sit still, you want to slow down gradually.

    But what I originally meant was “stop braking HARD and let the brakes cool,” not literally stop immediately wherever you are and let the car sit.

    Bummer, should have been more concise.

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