Brake Fade and Brake Fluid Boil
What is brake fade?
Brake fade happens when too much heat created by friction prevents brakes from working properly. Though it comes in many forms, it can happen more often when you have more weight in or attached to your vehicle.
However, there are things you can do to prevent this from happening. Understanding why you might experience brake fade or poor braking performance is essential to preventing it from happening, or regaining control of your vehicle if it does happen.
Why does reduced braking performance happen?
There are two main causes of this phenomenon. Both have different signs and symptoms, so you’ll want to know about both before you set out with your truck and trailer.
Brake Fluid boil
The symptoms of brake fluid boil are commonly mis-interpreted as brake fade. Brake fluid boil makes the brake pedal feel spongy or go straight to the floor when applied, but in case of true brake fade, the pedal feels normal.
During periods of increased braking such as mountainous driving, trailer towing, or high-speed stops, heat can be transferred to the brake caliper, dramatically increasing the brake fluid temperature. Brake fluid naturally attracts and absorbs water. If the fluid has absorbed water, the boiling point is reduced dramatically. Between the dramatic increase in temperature and the lower boiling point, the brake fluid can easily boil. This boiling can create air bubbles in the brake system. Unlike the brake fluid, the air bubbles will easily compress during braking, and when it does, it can cause the brake pedal to go straight to the floor without the vehicle slowing.
Brake pad fade
With brake fade, the pedal still feels normal, but the vehicle is not slowing down as you would expect. You’ll typically be able to smell the brake pads overheating, and though the brakes are applied, the vehicle isn’t stopping well.
The friction created by the brake pads and rotors is used to slow the vehicle. This friction or effectiveness tends to increase as the braking temperature increases, but above certain temperatures the brake pads begin to break down. Gasses can be released as the brake pad material breaks down, these gasses form a microscopic layer between the pad and rotor reducing friction. This decrease in braking effectiveness is considered brake fade.
Now, factor in a trailer to the equation. With more weight that your vehicle’s brakes are responsible for stopping, they will create more heat, and therefore increase the chance of brake fade.
How to handle brake fade and/or fluid boil
If you feel any of these symptoms, you’ll want to stop the vehicle. Sometimes using a lower gear can be useful to reduce speed.
In the event that fluid boil is experienced, and the vehicle is still moving, rapidly pump the brake pedal until the vehicle comes to a safe stop.
Once you’ve stopped the vehicle safely, you’ll need to let the brakes sit to cool. That said, they’re extremely hot, so don’t try to touch any part of them. Letting them cool is the only way to handle brake fade.
If the brakes still are not working properly after they’ve cooled off to a reasonable, ambient temperature, you’ll need to have your brakes checked out by a mechanic for other problems.
How to prevent fluid boil and brake fade
Knowing how to handle these conditions doesn’t mean that you shouldn’t take steps to prevent it.
An easy way to prevent brake fade and fluid boil is a no-brainer: to keep them from getting too hot. When towing, especially downhill, don’t drag the brakes. Firmly applying and releasing the brakes will give them a chance to cool. This can help prevent brake fade and fluid boil.
Another easy way to save your brakes is to drop your vehicle’s transmission to a lower gear. This will have the engine help to hold your truck back while going down a long, steep hill.
Keeping your brake fluid fresh is another important preventative measure. Bleed the brakes fully and replace the fluid when recommended. While many don’t consider changing brake fluid often, manufacturers generally recommend doing a flush every two years.
Perhaps the best way to reduce to possibility of brake pad fade is by upgrading your vehicle braking system by installing performance brake pads and rotors, such as PowerStops Z36 Extreme Truck and Tow brake package. You’ll want to look for a drilled and slotted rotor to help cool the pads by increasing airflow. Carbon fiber ceramic pads can stand up to the increased heat better as well. Better rotors and pads will help your brakes keep up with your truck when it needs to stop.
Though brake fade might be more common during towing, it doesn’t have to be. By keeping up with your truck’s maintenance and braking system, brake fade and fluid boil are easily preventable. Towing downhill can be strenuous on your truck’s brakes, but if you’ve properly hooked up your trailer, are towing a reasonable load for your vehicle, and have taken precautions against brake overheating, your truck and trailer should be good to go.
Don’t Just Stop… PowerStop!