brake upgrade includes Centric Posi Quiet Brake Pads, StopTech
Stainless Steel Front Brake Lines, StopTech slotted front
and rear rotors, and three bottles of StopTech STR600 synthetic brake fluid. A
stage 2 brake upgrade kit will fit your stock calipers, and is an
excellent choice for the enthusiast whose rotors are nearing the end of
their service life, the StopTech Stage 2 kit includes all the components
and benefits provided by the Stage 1 kit, but adds value through the
addition of direct replacement slotted rotors at all four corners.
About Centric Posi Quiet Brake Pads
Posi Quiet pads from
Centric Parts offer the solution to dirty rims, and noisy brakes.
Posi Quiet Pads use technology which perform with the same quality
of stock pads or even better, while making almost no dust or noise.
All Posi Quiet brake pads are manufactured using the same positive
molding process utilized by OE (Original Equipment) suppliers. These
pads solve the main
problems with other brake pads such as noise and vibration. Centric
recognized these issues and ensures proper fitment in the caliper
virtually eliminating noise associated with pad vibration.
Eliminate dust and dirt on your rims
Noise from your brakes
Optimum braking performance for SUVs, and trucks
StopTech Stainless Steel Brake Lines
StopTech Stainless Steel Brake Lines improve pedal feel and reduce the
amount of time between applied pedal pressure and actual deceleration by
preventing expansion. This provides
a quicker pedal response, and allows the driver to maintain consistent
brake pressure and precision brake modulation. StopTech Stainless Steel
Brake Lines are 100% DOT compliant and can withstand pressures of
4500 PSI. StopTech brake lines consist of a Teflon inner line that is covered
with a layer of stainless steel woven braid. The Teflon tube is
resistant to expansion while under pressure and will not degrade from
being exposed to brake fluid.
StopTech Slotted Rotors
SportStop Slotted Rotors will fit your vehicles stock calipers and
provide increased stopping power over OE. Slotted rotors add more
"bite" to your brakes, and prevent your brake pad from glazing.
Quality is ensure because SportStop Slotted Rotors are manufactured to
meet or exceed factory rotor specifications.
Part Number Reference Guide
1998 - 2004 Jetta Mk4
Centric Brake Pads F/R
109.06870 / 109.03400
SS Brake Lines
StopTech Brake Fluid (3 pack)
Stainless Steel Brake Lines Q&A
Walker, Jr. of scR motorsports
Why are flexible brake hoses used in the first place?
From the factory, nearly every production passenger car has short, flexible
hoses that run from the fixed, hard metal brake tubes to the calipers (or wheel
cylinders as the case may be). These flexible hoses are necessary because the
wheel ends are free to move relative to the body of the vehicle. Inflexible
tubes would not allow for the articulation of the wheel ends without subsequent
What are OEM hoses made from?
Typically, OEM hoses contain a compliant polymeric inner hose to transmit
brake fluid pressure from the brake tubes to the caliper. While the polymeric
tube itself does a good job of withstanding attack from the brake fluid, it must
be protected from the outside world and is consequently wrapped (overmolded)
with a thick, rubber coating. Hollow fasteners at one or both ends of the hose
provide a direct flow path and a leak-free connection system.
So how are Stainless Steel lines different?
Stainless Steel lines (they are actually hoses, but we'll use the common term
“lines” from this point forward in this FAQ) are similar to OEM hoses in
function, but differ greatly in execution. Unlike OEM hoses, SS lines
incorporate a low-compliance Teflon inner hose. In addition, instead of covering
the Teflon with overmolded rubber a woven braid of Stainless Steel strands is
placed over the hose for protection. As with an OEM hose, the ends are
terminated with hollow fasteners to allow for the leak-free passage of brake
So why is that better than the OEM rubber design?
Stainless Steel lines provide a number of benefits as compared to their OEM
rubber overmolded counterparts.
1. The SS braid provides superior protection from flying roadway debris.
2. The SS braid and Teflon hose reduce expansion during pressurization.
3. They provide the race car look.
I understand the protection benefit, but can you explain the reduced
Any time that an object is subjected to internal pressure, it expands. The
amount of expansion will be proportional to the amount of pressure present and
the rigidity of the holding structure. In the case of brake hoses, we are
subjecting Teflon to internal pressures as high as 3000PSI. Because the Teflon
is relatively flexible (which makes it ideal for the job in one regard), it will
expand under these conditions. This expansion creates additional fluid volume in
the hydraulic circuit which is felt by the driver as a soft or mushy pedal.
Rubber overmolding does little to reduce expansion under pressure, as rubber
is also a relatively flexible material. A woven braid of Stainless Steel,
however, can greatly increase the rigidity of the hose under pressure while
still allowing adequate flexibility for wheel end movement. In many cases, this
reduced expansion can be felt by the driver as a firmer or more responsive brake
In addition, the reduced compliance will result in a faster transient
response of the brake system. In other words, the time from the driver hitting
the brake pedal until deceleration is generated will be decreased by a small
amount. The benefit will vary based on each individual application, but in
general overall deceleration can be attained more quickly, resulting in slightly
shorter stopping distances.
What impacts will SS lines have on my vehicle's P-T (pressure vs. torque)
None. Because brake lines and hoses do not affect the torque generated at the
wheel end, the P-T relationship remains unchanged when SS lines are installed.
Only changes to a vehicle's caliper, rotor, or brake pad coefficient of friction
will impact the P-T relationship.
Well then, will SS lines impact my vehicle's P-V (pressure vs. volume)
Absolutely. Because SS lines are much less compliant than their OEM
counterparts, the P-V relationship will be reduced to some degree (less volume
will be required at a given pressure). This is exactly the reason that a car
equipped with SS lines has a firmer brake pedal.
However, because the P-T relationship remains unchanged with SS lines, the
impact to ABS, TCS, and other brake control systems is typically negligible. Our
own BBK kit testing indicates that most ABS, TCS, and other brake control
systems are robust to the small changes affected by the addition of SS lines. On
the other hand, testing at StopTech (and at major OEMs as well) has shown that
while decreases in the P-V relationship typically are invisible to SS lines,
increases in the P-V relationship are not (as would be found with an
In summary, because SS lines and a properly sized and balanced BBK only serve
to reduce the P-V relationship, we have time and time again demonstrated
appropriate system integration with these products. Our in-house testing allows
us to make this statement for every platform we service.
Will I feel a difference on my car if I install SS lines?
The amount of perceived difference will vary by each car's individual design,
age, and usage. Those cars with a significant amount of flexible OEM line or
those that have seen years or use and aging will typically display a more
dramatic improvement in pedal feel than new cars with shorter lines.
What is the difference between lines that are “DOT compliant” and “DOT
The United States Department of Transportation (DOT) has established numerous
standards for automotive components and subsystems. The regulation for brake
hoses happens to be FMVSS106. In this document, anything and everything
pertaining to automotive brake hoses has been laid out in gory detail – at
least, those things important to the federal government.
If a manufacturer claims their SS lines are “DOT compliant”, it means that
their SS lines have passed all FMVSS106 requirements, and they have submitted
the test data to the government for official certification. This does not mean
they are acceptable for use on your car, but it does mean they pass the
government minimum standards.
Another term you may hear in this context is “DOT approved.” However, the DOT
is not in the business of actually approving or disproving compliance – they
don't typically run any tests on aftermarket components themselves. Under these
circumstances, one can only surmise that these manufacturers are trying to state
that their lines are actually “DOT compliant”, but it never hurts to ask before
So, do I need to use only DOT compliant SS lines on my car?
Not necessarily. The DOT requirements must be met in full for official
government approval, so even if a SS line passes every performance test but is
labeled with the wrong type of tag (or something equally trivial) it would fail
certification. While this might mean something to an auto manufacturer or
assembly plant, it is meaningless to the performance enthusiast.
All the DOT compliance means is that the lines have passed a minimum set of
government standards which may or may not be important to you. Does this mean
that DOT compliant lines are the best for your car? Not necessarily, but the
certification should indicate that the manufacturer understands the product and
is trying to hold itself to a certain standard.
Why do some SS lines have a clear plastic covering?
Under certain conditions, dirt and other abrasive contaminants can find their
way between the SS braid and the Teflon inner hose. Over time these contaminants
can be ground into the Teflon line to the point that a leak can develop.
Naturally, a leak in the brake system is never a good thing.
Some manufacturers have taken the extra step to cover the SS braid with a
polymeric coating to prevent contaminants from working their way into the Teflon
liner. While this coating is not necessary for short-term longevity, hoses
without the coating should be inspected and replaced on a more frequent basis.
Why do some SS lines have plastic molded over the end fittings?
Some SS line manufacturers have adopted the practice of molding a semi-rigid
polymer over the fittings at either or both ends of the line. These features act
as a strain relief for the SS braid where the fitting is secured to the line. In
some cases, lines without these features can fail certain dynamic portions of
FMVSS106, as the SS braid can wear itself into the Teflon line where it is
secured to the end fitting.
Do I need to take any special precautions when installing my SS lines?
In general, no. The most important thing to note is that the routing of the
SS line should match either the original stock routing or the instructions
included for a new routing (if applicable). Because the SS braid will eventually
wear through just about anything (once the protective outer layer is worn away),
be sure that there is adequate clearance to all other moving parts under
conditions of full wheel travel and full steering.
It should also be mentioned that after installation care should be taken to
examine your SS line routing to ensure that the line is not stressed when the
wheels are turned to full lock. This is best done with the wheel hanging at full
droop to amplify any routing concerns. Of course the line should never come in
direct contact with any part of the tire, but the line should not be pulled
radially with respect to the overmolded end fittings either.
How to Bleed Brakes – The Right Way
by John Comeskey of SPS
Walker, Jr. of scR motorsports
The role of the brake fluid within the braking system is to transfer the
force from the master cylinder to the corners of the car…and a vital
characteristic of brake fluid that allows it to perform its task properly is its
ability to maintain a liquid state and resist compression. In order to keep the
fluid in top condition, many enthusiasts have been taught to “bleed their
brakes” but many have never stopped to ask the question “why?”
Why Bleed the Brakes?
The term "bleeding the brakes" refers to the process in which a small valve
is opened at the caliper (or wheel cylinder) to allow controlled amounts of
brake fluid to escape the system. (When you think about it, "bleeding" may
appear to be a somewhat graphic term, but it aptly describes the release a vital
We bleed the brakes to release air that sometimes becomes trapped within the
lines. Technically, "air" only enters the lines if there is a compromise of the
system's sealing (as when flex lines are removed or replaced), because when
fluid boils, it will instead create "fluid vapor." Vapor in the brake fluid,
like air, will create an efficiency loss in the braking system. However, for the
sake of simplicity we use the term "air" throughout this article to describe
both air and fluid vapor.
When air (or vapor) becomes present within the lines, it creates
inefficiencies within the system because, unlike liquid, air can be compressed.
So when enough air fills the lines, input at the pedal merely causes the air to
compress instead of creating pressure at the brake corners. In other words, when
air is present within the system, the efficiency and effectiveness of the
braking system is reduced. Usually, a small amount of air within the brake
system will contribute to a "mushy" or "soft" pedal (since less energy is
required to compress the air than is required to move fluid throughout the brake
lines.) If enough air enters the brake system, it can result in complete brake
So how does air enter the lines in the first place? Sometimes, it can be the
result of a service procedure or an upgrade – such as replacing the stock flex
lines with stainless steel braided lines. But often it is the result of high
temperatures that cause brake fluid components to boil, thus releasing gasses
from the boiling fluid into the brake hydraulic system.
Brake Fluid Selection
This leads one to contemplate the type of liquid that is used as brake fluid.
In theory, even simple water would work – since, being a liquid, water cannot be
compressed. However, it is important to remember that the fundamental function
of the braking system is to convert kinetic energy into heat energy through
friction. And the reality of this process is that certain parts of the braking
system will be exposed to very high temperatures. In fact, it is not uncommon to
see rotor temperatures during a race as high as 1200 degrees Fahrenheit – which
can raise the temperature of the brake fluid to well over 300 degrees
Fahrenheit. Since the boiling point of water is 212 degrees Fahrenheit, it is
easy to see that water within the brake system could boil easily – and therefore
release gases into the brake pipes – which would reduce the efficiency of the
system. (Water would also present a big problem in cold weather if it froze to
The "obvious" solution to this problem is to utilize a fluid that is less
sensitive to temperature extremes. Hence the development of "brake fluid."
However, there unfortunately is no such thing as a "perfect" brake fluid. And
like most things in the world, the addition of certain beneficial
characteristics usually brings tradeoffs in other areas. In the case of brake
fluid, we generally must balance the fluid's sensitivity to temperature against
its cost and its impact upon other components within the system.
Stated more bluntly, it is possible to reduce a fluid's sensitivity to
temperature by varying the ingredients of the fluid. However, certain
combinations of ingredients can significantly increase the cost of the fluid and
may react with OEM materials to damage seals and induce corrosion throughout the
The chemical composition and minimum performance requirements of the fluid
are generally indicated through a rating such as "DOT3," DOT4," or "DOT5." The
DOT-rating itself is assigned after a series of government tests. However, this
rating is NOT intended to indicate boiling points, even though higher DOT
ratings generally do correspond with higher boiling points. Perhaps more
importantly, the DOT rating does indicate the base compound of the brake fluid -
which allows manufacturers to specify fluid types which are less likely to react
negatively to known materials used within a particular braking system.
The greatest irony about brake fluid, however, is the fact that the chemical
compositions that tend to be less sensitive to temperature extremes also tend to
attract and absorb water! So even though the fluid itself is unlikely to boil
(most glycol-based DOT3 fluids have a "dry boiling point" around 400 degrees
Fahrenheit,) the water that it absorbs over time tends to boil easily (at 212
degrees Fahrenheit.) It is this characteristic of absorbing moisture that leads
to the measure known as the "wet boiling point." The wet boiling point is the
equilibrium boiling point of the fluid after it has absorbed moisture under
specified conditions. Because brake fluid will absorb moisture through the brake
system's hoses and reservoir, evaluation of the wet boiling point is employed to
test the performance of used brake fluid and the degradation in it's
performance. (And it is why we still need to bleed the brakes frequently on
racecars, even though we use racing fluid that costs upwards of $75 per bottle!)
The lesson: do NOT expect to avoid bleeding your brakes just because you bought
expensive brake fluid.
As one might guess, "racing" fluids will use relatively "aggressive" chemical
compositions which will tend to have higher wet boiling points and higher costs,
while the average street fluids will use more conservative compositions which
will have lower wet boiling points and lower costs. In some cases – such as a
purpose-built racecar – the tradeoffs of using the expensive racing fluid is
outweighed by the competitive advantages. But for the average driver – whose
driving style is less likely to induce brake temps as high as those seen on the
track – the costs of the fluids and potential wear-and-tear factors upon system
components may justify the use of a more conservative fluid with a lower wet
So, now that you understand the need behind bleeding your brakes, let us
present just one procedure that can be utilized when servicing your own car.
Note that unless you are replacing your master cylinder, the procedure is the
same whether you have a vehicle equipped with ABS or not…
You will need the following tools:
· Box-end wrench suitable for your car's bleeder screws. An offset head design
usually works best.
· Extra brake fluid (about 1 pint if you are just bleeding, about 3 if you are
· 12-inch long section of clear plastic tubing, ID sized to fit snugly over your
car's bleeder screws.
· Disposable bottle for waste fluid.
· One can of brake cleaner.
· One assistant (to pump the brake pedal).
Vehicle Preparation and Support
1. Loosen the lug nuts of the road wheels and place the entire vehicle on
jackstands. Be sure that the car is firmly supported before going ANY further
with this procedure!
2. Remove all road wheels.
3. Install one lug nut backward at each corner and tighten the nut against the
rotor surface. Note that this step is to limit caliper flex that may distort
4. Open the hood and check the level of the brake fluid reservoir. Add fluid as
necessary to ensure that the level is at the MAX marking of the reservoir. Do
not let the reservoir become empty at any time during the bleeding process!
1. Begin at the corner furthest from the driver and proceed in order toward
the driver. (Right rear, left rear, right front, left front.) While the actual
sequence is not critical to the bleed performance it is easy to remember the
sequence as the farthest to the closest. This will also allow the system to be
bled in such a way as to minimize the amount of potential cross-contamination
between the new and old fluid.
2. Locate the bleeder screw at the rear of the caliper body (or drum brake wheel
cylinder.) Remove the rubber cap from the bleeder screw – and don't lose it!
3. Place the box-end wrench over the bleeder screw. An offset wrench works best
– since it allows the most room for movement.
4. Place one end of the clear plastic hose over the nipple of the bleeder screw.
5. Place the other end of the hose into the disposable bottle.
6. Place the bottle for waste fluid on top of the caliper body or drum assembly.
Hold the bottle with one hand and grasp the wrench with the other hand.
7. Instruct the assistant to "apply." The assistant should pump the brake pedal
three times, hold the pedal down firmly, and respond with "applied." Instruct
the assistant not to release the brakes until told to do so.
8. Loosen the bleeder screw with a brief ¼ turn to release fluid into the waste
line. The screw only needs to be open for one second or less. (The brake pedal
will "fall" to the floor as the bleeder screw is opened. Instruct the assistant
in advance not to release the brakes until instructed to do so.)
9. Close the bleeder screw by tightening it gently. Note that one does not need
to pull on the wrench with ridiculous force. Usually just a quick tug will do.
10. Instruct the assistant to "release" the brakes. Note: do NOT release the
brake pedal while the bleeder screw is open, as this will suck air back into the
11. The assistant should respond with "released."
12. Inspect the fluid within the waste line for air bubbles.
13. Continue the bleeding process (steps 11 through 16) until air bubbles are no
longer present. Be sure to check the brake fluid level in the reservoir after
bleeding each wheel! Add fluid as necessary to keep the level at the MAX
marking. (Typically, one repeats this process 5-10 times per wheel when doing a
14. Move systematically toward the driver – right rear, left rear, right front,
left front - repeating the bleeding process at each corner. Be sure to keep a
watchful eye on the brake fluid reservior! Keep it full!
15. When all four corners have been bled, spray the bleeder screw (and any other
parts that were moistened with spilled or dripped brake fluid) with brake
cleaner and wipe dry with a clean rag. (Leaving the area clean and dry will make
it easier to spot leaks through visual inspection later!) Try to avoid spraying
the brake cleaner DIRECTLY on any parts made of rubber or plastic, as the
cleaner can make these parts brittle after repeated exposure.
16. Test the brake pedal for a firm feel. (Bleeding the brakes will not
necessarily cure a "soft" or "mushy" pedal – since pad taper and compliance
elsewhere within the system can contribute to a soft pedal. But the pedal should
not be any worse than it was prior to the bleeding procedure!)
17. Be sure to inspect the bleeder screws and other fittings for signs of
leakage. Correct as necessary.
18. Properly dispose of the used waste fluid as you would dispose of used motor
oil. Important: used brake fluid should NEVER be poured back into the master
Vehicle Wrap-Up and Road Test
1. Re-install all four road wheels.
2. Raise the entire vehicle and remove jackstands. Torque the lug nuts to the
manufacturer's recommended limit. Re-install any hubcaps or wheel covers.
3. With the vehicle on level ground and with the car NOT running, apply and
release the brake pedal several times until all clearances are taken up in the
system. During this time, the brake pedal feel may improve slightly, but the
brake pedal should be at least as firm as it was prior to the bleeding process.
4. Road test the vehicle to confirm proper function of the brakes. USE CAUTION
THE FIRST TIME YOU DRIVE YOUR CAR AFTER MODIFICATION TO ENSURE THE PROPER
FUNCTION OF ALL VEHICLE SYSTEMS!
How Often do I Need to Bleed My Brakes?
In closing, here are a few rules of thumb to help you to determine the proper
bleeding interval for your particular application:
1. Under normal operating conditions, and without brake system modifications,
typical OEM braking systems have been designed to NOT require bleeding for the
life of the vehicle unless the system is opened for repair or replacement. If
you're just driving around town or on the highway to work, there is really no
need to bleed! There are a few European vehicles which do recommend replacement
on a semi-regular basis for other reasons though, so be sure to check in your
owner's manual or at your service center for your particular application.
2. Those who choose to autocross or drive in a sporting manner may choose to
upgrade their brake fluid and bleed on an annual basis – this is a good ‘start
of the season' maintenance item for low-speed competitors.
3. If your car sees significant amounts of high-speed braking, or if you choose
to participate in driver schools and/or lapping sessions, bleeding prior to each
event is a sound decision. More intense drivers at these events may choose to
skip right past this step and on to #4…
4. Finally, dedicated race cars should be bled after every track session.
Pad and Rotor Bed-In Theory, Definitions and Procedures
Removing the Mystery from Brake Pad Bed-In
by Matt Weiss of StopTech and
James Walker, Jr.
of scR motorsports
In order for any brake system to work optimally, the rotors and pads must be
properly bedded-in, period. This process can also be called break-in,
conditioning, or burnishing, but whatever terminology you choose, getting the
brakes properly bedded-in and keeping them that way is critical to the peak
performance of the entire brake system.
However, understanding why the rotors and pads need to be bedded-in is just
as important as the actual process. If one understands what is happening during
the bed-in process, they can tailor the process to specific pads, rotors, and/or
driving conditions. For this reason, we present this generic bed-in overview
pertaining to all brake systems, but follow with links to application-specific
bed-in procedures to fit most every set of circumstances.
What is brake pad “bed-in” anyway?
Simply stated, bed-in is the process of depositing an even layer of brake pad
material, or transfer layer, on the rubbing surface of the rotor disc. That's
it. End of discussion. Ok, not really, but although bed-in is quite basic in
definition, achieving this condition in practice can be quite a challenge, and
the ramifications of improper or incomplete bed-in can be quite a-a-n-n-o-o-y-y-i-i-n-n-g-g.
Abrasive friction and adherent friction
There are two basic types of brake pad friction mechanisms:
and adherent friction
. In general, all pads display a bit of each, with abrasive mechanisms
dominating the lower temperature ranges while adherent mechanisms come more into
play as pad temperature increases. Both mechanisms allow for friction or the
conversion of Kinetic energy to Thermal energy, which is the function of a brake
system, by the breaking of molecular bonds in vastly different ways.
The abrasive mechanism generates friction or energy conversion by the
mechanical rubbing of the brake pad material directly on the rotor disc. In a
crystalline sense, the weaker of the bonds in the two different materials is
broken. This obviously results in mechanical wear of both the pad and the rotor.
Consequently, both pads and rotors are replaced when they are physically worn to
their limit and are too thin to endure further service.
The adherent mechanism is altogether different. In an adherent system, a thin
layer of brake pad material actually transfers and sticks (adheres) on to the
rotor face. The layer of pad material, once evenly established on the rotor, is
what actually rubs on the brake pad. The bonds that are broken, for the
conversion of Kinetic to Thermal energy, are formed instantaneously before being
broken again. It is this brake pad-on-transferred brake pad material interaction
on a molecular level that yields the conversion process.
With the adherent mechanism there is much reduced rotor wear as compared to
abrasive mechanism, but it's not a free lunch – pads now become the primary wear
element in the braking system. And even though rotors are not mechanically worn
down with adherent systems, they still will need to be replaced on a regular
basis due to cracking reaching a point of failure if they are exposed to
intense, repetitive thermal cycling. This is why race teams throw out rotors
that are actually as thick or thicker than when they were brand new. It's due to
the an adherent brake pad transfer layer!
The all-important transfer layer
As stated above, the objective of the bed-in process is to deposit an even
layer of brake pad material, or
transfer layer ,
on the rubbing surface of the rotor disc. Note the emphasis on the word even, as
uneven pad deposits on the rotor face are the number one, and almost exclusive
cause of brake judder or vibration.
Let's say that again, just so there is no misunderstanding. Uneven pad
deposits on the rotor face are the number one, and almost exclusive cause of
brake judder or vibration.
It only takes a small amount of thickness variation, or TV, in the transfer
layer (we're only talking a few ten thousandths of an inch here) to initiate
brake vibration. While the impact of an uneven transfer layer is almost
imperceptible at first, as the pad starts riding the high and low spots, more
and more TV will be naturally generated until the vibration is much more
evident. With prolonged exposure, the high spots can become hot spots and can
actually change the metallurgy of the rotor in those areas, creating “hard”
spots in the rotor face that are virtually impossible to remove.
In general, bed-in consists of heating a brake system to its adherent
temperature to allow the formation of a transfer layer. The brake system is then
allowed to cool without coming to rest, resulting in an even transfer layer
deposition around the rotor circumference. This procedure is typically repeated
two or three times in order to ensure that the entire rotor face is evenly
covered with brake pad material. Sounds easy, right? Well, it can be if you have
the proper information.
Because the adherent temperature range for brake pads varies widely
(typically 100°F-600°F for street pads and 600°F-1400°F for race pads), each
bed-in needs to be application-specific. One could try to generate a
one-size-fits-all procedure, but too little heat during bed-in keeps the
material from transferring to the rotor face while overheating the system can
generate uneven pad deposits due to the material breaking down and splotching
(that's a technical term) on to the rotor face.
In summary, the key to a successful bed-in is to bring the pads up to their
adherent operating temperature in a controlled manner and keep them there long
enough to start the pad material transfer process. Different brake system
designs, pad types, and driving conditions require different procedures to
successfully accomplish the bed-in. The recommended procedures below should
provide you with the information you need to select the bed-in procedure
appropriate for your application.
StopTech's Recommended Procedure for Bedding-in Stock-Sized Brake Systems
by Matt Weiss of StopTech and
James Walker, Jr.
of scR motorsports
When a system has both new rotors and pads, there are two different objectives
for bedding-in a performance brake system: heating up the brake rotors and pads
in a prescribed manner, so as to transfer pad material evenly onto the rotors;
and maturing the pad material, so that resins which are used to bind and form it
are ‘cooked' out of the pad.
The first objective is achieved by performing a series of stops, so that the
brake rotor and pad material are heated steadily to a temperature that promotes
the transfer of pad material onto the brake rotor friction surface. There is one
pitfall in this process, however, which must be avoided. The rotor and,
therefore, the vehicle should not be brought to a complete stop, with the brakes
still applied, as this risks the non-uniform transfer of pad material onto the
The second objective of the bedding-in process is achieved by performing
another set of stops, in order to mature the pad itself. This ensures that
resins which are used to bind and form the pad material are ‘cooked' out of the
pad, at the point where the pad meets the rotor's friction surface.
The bed-in process is not complete until both sets of stops have been
Bedding-in Street Performance Pads
For a typical performance brake system using street-performance pads, a
series of ten partial braking events, from 60mph down to 10mph, will typically
raise the temperature of the brake components sufficiently to be considered one
bed-in set. Each of the ten partial braking events should achieve
moderate-to-high deceleration (about 80 to 90% of the deceleration required to
lock up the brakes and/or to engage the ABS), and they should be made one after
the other, without allowing the brakes to cool in between.
Depending on the make-up of the pad material, the brake friction will seem to
gain slightly in performance, and will then lose or fade somewhat by around the
fifth stop (also about the time that a friction smell will be detectable in the
passenger compartment). This does not indicate that the brakes are bedded-in.
This phenomenon is known as a green fade, as it is characteristic of immature or
‘green' pads, in which the resins still need to be driven out of the pad
material, at the point where the pads meet the rotors. In this circumstance, the
upper temperature limit of the friction material will not yet have been reached.
As when bedding-in any set of brakes, care should be taken regarding the
longer stopping distance necessary with incompletely bedded pads. This first set
of stops in the bed-in process is only complete when all ten stops have been
performed - not before. The system should then be allowed to cool, by driving
the vehicle at the highest safe speed for the circumstances, without bringing it
to a complete stop with the brakes still applied. After cooling the vehicle, a
second set of ten partial braking events should be performed, followed by
another cooling exercise. In some situations, a third set is beneficial, but two
are normally sufficient.
Bedding-in Club Race or Full Race Pads
For a typical performance brake system using race pads, the bed-in procedure
must be somewhat more aggressive, as higher temperatures need to be reached, in
order to bring certain brands of pad material up to their full race potential.
We typically recommend a set of ten partial braking events, from 60mph down
to 10mph, followed immediately by three or four partial braking events, from
80mph down to 10mph. Alternately, a set of eleven stops, from 80mph to 40mph, or
a set of seven stops, from 100mph to 50mph, would be approximately the same. As
with street pads, each of the partial braking events should achieve
moderate-to-high deceleration (about 80% of the deceleration required to lock up
the brakes and/or to engage the ABS), and they should be made one after the
other, without allowing the brakes to cool in between.
Again, depending on the make-up of the pad material, the brake friction will
seem to gain slightly in performance, and will then lose or fade somewhat about
halfway through the first set of stops. This does not indicate that the brakes
are bedded-in, except where race-ready pads are being used. This phenomenon is
the same as that which occurs with high-performance or street pads (except that,
when race-ready pads are used, they do not exhibit green fade, and they will be
bedded-in after just one complete set of stops).
As when bedding-in any set of brakes, care should be taken regarding the
longer stopping distance necessary with incompletely bedded pads. This first set
of stops in the bed-in process is only complete when the recommended number of
stops has been performed - not before. As a general rule, it would be better to
perform additional stops, than not enough. The system should then be allowed to
cool, by driving the vehicle at the highest safe speed for the circumstances,
without bringing it to a complete stop with the brakes still applied.
After cooling the vehicle, a second set of the recommended number of stops
should be performed, followed by another cooling exercise. In some situations, a
third set is beneficial, but two are normally sufficient.
Racers will note that, when a pad is bedded-in properly, there will be
approximately 2mm (0.1 inch) of the pad edge near the rotor, on which the paint
will have turned to ash, or the color of the pad will have changed to look as
though it has been overheated.
In summary, the key to successfully bedding-in performance brakes is to bring
the pads up to their operating temperature range, in a controlled manner, and to
keep them there long enough to start the pad material transfer process.
Different brake system designs, pad types, and driving conditions require
different procedures to achieve a successful bed-in. The procedures recommended
above should provide a useful starting point for developing bed-in procedures
appropriate to individual applications.
"Well I ordered a full set (front and rear) of the Centric Stop-Tech slotted
rotors and Centric Posi-Quiet brake pads for my '05 F-150. After only 35,000
miles the OEM rotors were warped to the point where they could not be safely
re-surfaced, according to the Ford dealer.
I ordered everything from Alon at Mod Bargains([email protected]). He was
very helpful on the phone and made sure that I had everything that I needed. I
was going to get Powerslot rotors, but they did not have them in stock at the
time so Alon suggested the Centric StopTech rotors. The total came to $545.20
including the shipping charges. Everything arrived on Monday in 2 very well
packaged boxes. Lot's of packing materials to keep things safe. I had a question
about shipping and tracking numbers and Mandy in customer service was extremely
helpful in getting all of the information to me and following up on my
Unfortunately, I did not have my camera available to take any pictures. The
rotors appeared to be of good quality, well machined with no visible sharp edges
or partially attached metal shavings. The slots were also quite smooth with no
sharp edges. The pad surface of the rotors have a phosphate coating and the rest
of the rotor is also covered, not sure if it is a powder coat or just painted.
Either way, that should help in keeping down the rust of the outside edges of
I don't really know what to say about the pads. They appeared to be of good
quality, but I don't really know what to look for when inspecting brake pads.
They looked plenty thick enough to me and seemed to be bonded real good. Duh.
I had everything installed by my local mechanic. He also performed the bed-in
procedure and flushed/bled the brake fluid. He told me that everything installed
by the book with no problems at all. After bedding in the brakes he was
impressed with the difference from the OEM brakes but still felt that the brakes
were a little soft. Bleeding the system made a big difference in pedal firmness.
The brakes haven't been in for very long, but I already feel like they are much
better than the OEM brakes. The original brakes always felt a little soft to me.
I had them checked when the truck was at about 2,000 miles and was told by the
dealership that they were fine. I got into the habit of pumping once before
applying the brakes. That no longer feels necessary.
Everyone I talked with at Mod Bargains was very helpful and knowledgeable of
their products. I would have no problem going back to them for any other
products that they sell."