Frequently Asked Questions
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Racing brake pads are made from a variety of ingredients like metals, resins and fillers. The combination of ingredients and the size and weight of the ingredients used in the friction formula can create very different performance levels and characteristics.
Choosing the proper brake pad
compound that will provide the best performance for your
motorsports application can be made easier by following some guidelines.
- Determine what compounds and styles
of brake pads are available for your calipers and type of racing.
- Determine the operating temperature of
your cars brake system. Heat sensitive paint can be applied
to the brake pads and rotors to help you gauge temperature. Tire
pyrometers can be used but due to the cool down time the
temperature numbers may not be accurate.
- Upon learning your system's temperatures, or if you
do not know your temperatures contact Hawk Performance
for recommendations regarding proper brake material for
- Other drivers that share your driving style will sometimes
provide valuable information that may allow you to learn
what brake pads other drivers have used and liked or disliked.
- Contact your local racing products dealer and inquire
as to what brake pads they offer and recommend for your application.
- It’s important to understand
different types of racecars, racing surfaces and driving
styles may require different levels of braking performance,
and many drivers expect the brake system to have a certain
feel that suits their individual needs. Because of this,
it should not be assumed that what works for one driver
would work for all. In some cases the best way to learn
what is best for you is to experiment with a variety
of friction compounds to determine how a particular pad
differs from another regarding issues such as pedal feel,
consistency, and rotor and brake pad wear.
Note: Hawk Performance has also listed
a summary of compounds with application recommendations on
the Motorsports index (click
here to view).
When a friction compound is
used in a substantially higher temperature range than intended,
the material can quickly lose its ability to perform correctly.
Generally an overheated brake pad will continue to provide a hard
pedal but require more foot and pedal effort to achieve even
marginal performance. Continued use during this type of circumstance
can result in complete brake pad failure.
- It’s important to understand the chain of events
that take place when a brake pad becomes too hot to work
correctly. As the pad begins to lose performance effectiveness
the driver may try to compensate by pushing harder and
longer on the pedal. This may cause friction surface temperature
to increase thereby increasing the brake problem. When
this occurs, great stress is put on the friction material
and the material can begin to crystallize. In extreme cases
delaminating between the friction material and the pad's
backing plate can sometimes occur. This type of situation
may be corrected by choosing a friction compound designed
to withstand higher temperature.
Correct brake pad break-in (bedding) is important
to assure quality braking performance over the life of the pad. This procedure
allows the rubbing surface of the brake pad to slowly be brought up to racing
temperatures. Proper bedding creates a transfer layer film of friction material
to be applied to the rotor surface. This allows the brake pad material to rub
against itself rather than the bare rotor. This increases the stopping performance
of the brake pad and can reduce pad and rotor wear.
Brake pad break-in procedure.
- After reaching medium speed engage brake pedal to slow car without coming
to a complete stop. Release pedal quickly and do not drag brakes. Repeat
four or five times.
- At higher speeds engage brake pedal to slow car without
coming to a complete stop. Release pedal quickly and do not drag brakes.
Repeat five times.
- At or near race speed engage brake pedal to slow car
without coming to a complete stop. Release pedal quickly and do not drag
brakes. Repeat three times. Allow a few seconds between brake engagements
while car is in motion.
- Do not hold brake pedal. Park car for approximately
20 minutes or until brake rotors are completely cool to the touch.
during the above steps the brake pedal becomes soft or brake fade is
noticed, park the car immediately for approximately 20 minutes. Do not hold
- Do not attempt to use badly worn or damaged rotors with new brake pads.
- Do not drag brakes while car is moving during break-in procedure.
- Do not engage pedal while car is stopped at any time following the break-in
- Upon completing the procedure, allow the brake system to completely cool
- Applying the pedal a few times before the start of the race will allow
the brake pads to heat up before attempting to reach race speeds.
- Clean a used rotor surface with fine sand paper or steel wool, rinse with
water, dry and install before bedding new pads.
- Some forms of racing don't allow time for the proper break-in procedure
to be performed. However, it is still very important to attempt to perform
at least the core of the procedure: slow heat build up and complete cool
Proper break-in will assure that small amounts
of heat are introduced to the brake pad. Brake pads that are brought up to temperature
too fast and not properly allowed to cool down may quickly become glazed
and not perform as originally intended. The pads' rubbing surface reaches
extreme heat levels during racing use. The surface needs slow temperature
increases to help prepare the pad. Large amounts of heat all at one time
can cause the brake pad rubbing surface to become somewhat liquefied and coat the
pad surface with a glaze. This will dramatically reduce stopping performance
as certain ingredients in the friction compound break down and cause glazing
of the rubbing surface of the brake pad.
When a brake pad glazes over the friction
surface develops a cloudy or glassy looking coating. It is possible to
remove the glazed surface by using sand paper to grind away the damaged
layer and expose a new layer that will require the proper bedding procedure.
Some brake pad manufactures offer a pre-bedded
pad and/or a pre-bedding service. Pre-bedding is performed by placing a pad
in a caliper and running them with a mechanical driven rotor. The rotor and
pads are then slowly brought up to temperature and allowed to cool down over
several cycles. This process simulates on track situations while the two
surfaces mate correctly. While this process can be very expensive, it
greatly reduces the break-in time prior to pad purchase. In most cases the
rotor and the pad would then be sold as a matched set.
Some brake pads are pre-burnished during the
manufacturing process. Pads that are pre-burnished in this way have had high
temperature applied to the rubbing surface to simulate the first few engagements
on an actual racecar. The process will allow the pad to break-in quickly
and to begin working more effectively in a shorter time. Pre-burnished pads
still need to be properly bedded to help assure that the pad and the rotor have an
opportunity to mate correctly.