CALIPERS:
The Brembo one piece front calipers and two piece rear calipers offer the very best stopping power in a light weight, long life package. The pistons are aluminum with a titanium heat shield (or radiator) insert. The aluminum piston is designed to wear before the caliper body, allowing an inexpensive rebuild to put the caliper in like new condition. The radial mount design allows adjustment both parallel and perpendicular to the rotor. Another feature of the radial mount is that in a crash the caliper bracket will take the load usually saving the caliper from damage such as a broken or bent mounting ear. Brembo offers the best cooling caliper available for NASCAR.

Calipers should be mounted in a near vertical position to allow proper bleeding of air from the system. When the car is moving forward, the rotor should always first pass the small caliper piston then the large piston. On front mount (leading) calipers the small piston is on top; on rear mount (trailing) calipers the small piston is on the bottom. Consequently you can change a caliper from a front mount to a rear mount or vice-versa but you cannot make a RH caliper out of a LH or vise-versa. Calipers are marked with an arrow on the side of the caliper body indicating the direction of rotor rotation.

· It is important that the caliper centerline be no more than .020" off the rotor centerline and that the inside face of the caliper be parallel to the friction face of the rotor.
Calipers should be spaced out on the studs using the available shim kits (PN # BRE-SFCS & BRE-SRCS) to have at least .080" clearance between the rotor outer circumference and the caliper bridge. Most installations will see a larger clearance to maintain the pad outer radius near the rotor outer radius.
Ideally the difference between pad and rotor outer radius should be no more than .012" either way. When initially fitting the caliper and rotor, check this dimension with several sets of pads as the pad friction may be displaced on the steel backing plate giving an erroneous reading.
Ultimately this fit is in constant adjustment to maintain clearance between the wheel and the caliper bridge. The wheel is the component with the greatest dimensional variance or runout.
Pads must come in and out of the caliper without using force. Clearance between the pad and abutment plates and between the pads and rotor must be a minimum of .020".
Care must be taken to never over tighten the bleed screws. Over tightening will weaken the threads, increase the seat width and eventually cause problems.
Use Brembo copper washers when installing inlet fittings or banjo fittings in the calipers. Copper washers should only be installed and torqued once.

ROTORS:
Through research and development Brembo has engineered a factory-balanced rotor with a dynamic mounting system which has proved to have several advantages over the rigid design. As the brake system temperature migrates into the hub the tapered roller bearings can develop excess play. The expanding and contracting of the hub and bearings plus the flex of the spindle and other components results in the caliper centerline moving relative to the rotor centerline during braking. Brembo rotors are designed with .008" to .020" axial movement to allow the rotor to "seek" an optimal path through the caliper. The design also allows the rotor to move radially allowing growth in diameter with less distortion during braking. Rigid mounted rotors will "cone" at high breaking temperatures as a result of distortion. This can produce judder or pedal pulsation as the rotor distorts. The pulsation can be of high enough frequency that the driver does not feel it, however the actual stopping power is significantly reduced. The pulsation can become so bad that the car is hard to drive.

When installing rotor/hat assemblies check the float of the rotor after installation on the hub. A loss of float after all the lug nuts are tightened indicates that there are dings or burrs on the inside of the hat or on the face of the hub. This condition can cause several problems including rotor/wheel runout and brake drag. It is also possible with some studs for the knurl to protrude past the hub face after installation. This condition can also cause the hat to not seat flat against the hub resulting in a loss of float. Always check for this condition. The knurl will leave a witness mark on the stud hole inside of the hat. The solution is to remove the stud and turn down, to the correct diameter, that portion of the knurl that is proud of the hub. Chamfering the inside of the hat to clear the knurl only reduces the bearing surface of the hat on the stud and allows the problem to resurface if an un-chamfered hat is later installed.

Most of our rotors have directional vanes and directional groves. On heavy braking tracks, make sure that the rotors are installed in the correct direction of rotation to insure the best cooling efficiency. The directional vanes should run back from the inside to outside diameter and the groves should slant into the direction of rotation. Directional or curved vanes offer increased dimensional stability over straight vanes. The purpose of rotor groves is to add more bite and help clear away worn friction material from the face of the pads.

· The use of the front wheel bearing pre-load spacer kit
(PN # PSY-9150-PL) will minimize hub movement and improve overall braking performance and handling as well as increase the front wheel bearing and lubricant life in a NASCAR Stock Car.
· Check the float on the rotor after installation on the hub.
· Make sure that the knurl on the lug studs is not proud of the hub and/or drive plates.
· Premature cracks are usually caused by thermal shock.
· Hats and rotors should be cleaned with "brake clean" spray or any good non-oily solvent.
· At the track frequently check to insure that the wheels are rotating freely without any residual line pressure or pad drag and that there is no contact between the caliper and rotor or the caliper and wheel.
· Rotors and pads should be inspected after races and long practice/test runs.
· Rotors with cracks .200" long that have spread to the outside or inside edge and through the wall or cheek of the rotor should be replaced before a race or extended test run.
Rotors that have groves formed on the surface and/or show wear in thickness of more than .040" total when compared to a new rotor should also be replaced before a race.
With the modern metallic pads in universal use today it is not necessary to de-glaze pads or rotors. Sanding or glass bead blasting the friction surface of either diminishes performance.
· Simply fit newly bedded rotors and pads when the pads are worn out or the rotors are worn and/or cracked.

BEDDING - Brake Dynamometers
Pro-System brake bedding insures that all our rotors and pads are ready to run and require no further break-in consideration. We have two fully automated, computer controlled electric brake dynos that are used constantly for bedding, testing and development of brake parts. The fully automated bedding sequence uses the correct inertia and cycle time for the job to insure that you are getting the highest quality parts available and that they are the same time after time. Drivers and team personal have more than enough to be concerned with during a race weekend or a private test day. You do not have to waste valuable track time or money bedding brakes. To avoid thermal shock, with our bedded rotors as well as with any used rotor, they should be warmed up on the first lap. They do not have to be red hot, just warmed up and this will help prevent premature cracking that is common at some intermediate and speedway tracks (i.e. Charlotte).

BREMBO CUSTOM HATS:
While it is strongly urged that teams work within the standard size offerings, custom offset hats are available. Custom sizes are done in a minimum quantity of six parts, and delivery date is quoted at the time a purchase order is placed. No returns or exchanges are allowed on custom hats.

Only two dimensions are required for a custom hat; OVERALL HEIGHT (not the inside height) and MOUNTING FACE THICKNESS. To specify a custom hat, simply use the standard production hat part number and add a prefix that identifies the overall height first, and face thickness second.

Example:
BRE-80043 Hat (standard production part with 2.329" overall height with a face thickness of .250")

Because of a unique spindle set-up a team requires a different size hat. The order number of the new hat would be:enough to be concerned with during a race weekend or a private test day. You do not have to waste valuable track time or money bedding brakes. To avoid thermal shock, with our bedded rotors as well as with any used rotor, they should be warmed up on the first lap. They do not have to be red hot, just warmed up and this will help prevent premature cracking that is common at some intermediate and speedway tracks (i.e. Charlotte).

BRE-80043-2.079-.50 (this would yield a hat with an overall height of 2.079", and a face thickness of .50")

MASTER CYLINDERS:
The Brembo master cylinders are forged aluminum with a hard-anodized finish. They have the shortest, most consistent piston movement to make pressure of any cylinder available. They are specifically built for harsh racing environments and when installed properly will give a long service life. It is very important that the rubber dust boot always be in place.

Proper mounting of the master cylinders and pedal assembly are imperative to achieving optimal braking performance. Drivers can exert several hundred pounds of force on the pedal. If any movement or flexing occurs within the mounting or firewall it will give negative feedback to the driver. The spongy pedal the driver feels as a result of any flex can be incorrectly blamed on the pads or the hydraulic system.

Dual master cylinders allow you to have two independent hydraulic systems. The use of this set-up far outweighs a single unit. First and foremost is safety. In the event of a loss of front or rear brake the driver still has the other system available to stop the car. This can prevent the car from slowly rolling out of control across the track after hitting the wall and also enable it to stop in the pits. Also, front to rear bias can be adjusted using different size cylinders and then fine tuned with the balance bar adjuster.

The spherical bearing on the balance bar should always be near the center of the pedal housing. If, after balance is achieved, the bearing is to an extreme it will be necessary to change master cylinder size to bring it back to near center. Make sure the master cylinder mounting places the pushrods parallel with and on centerline with the cylinder bores. There should also be .040" clearance between each clevis and the pedal housing (.080" total). Both of the above, if set up improperly, can cause a binding or a shortened pedal stroke.

When initially setting the brake balance at the shop, be sure the balance bar is adjusted to be parallel to the firewall under braking after balance is achieved (use approximately 4SOpsi for setup). Adjust the balance bar to parallel by lengthening the shorter pushrod and shortening the longer pushrod equal amounts. Be sure to leave ample pushrod thread in the clevis for future adjustments, as adjustments may be necessary at the track if large bias changes are made.

SETTING BRAKE BIAS and PEDAL FEEL:
When setting brake bias and pedal feel, keep in mind that a smaller master cylinder diameter will yield more line pressure, more
pedal travel and less pedal effort for the same stopping power. The inverse is true when increasing master cylinder size. Initial bias should be set with approximately l2Opsi more front line pressure than rear. Ultimately the drivers' preference and feel will dictate the final setting but this is a good starting point.

Once a good brake balance is achieved at the track it is a good idea to take a line pressure reading front and rear for reference. This should also be done after a test or race if the driver indicates that the bias is correct. After a race inspect the pedal and balance bar assemblies, note their settings and how well the bar is centered and parallel to the firewall under the 4SOpsi test pressure. After all settings and pressures have been recorded then go through with routine disassembly, cleaning and service procedures.

· If a pedal return stop is used, make sure that the master cylinder pistons are allowed to fully return. Check this each time the assembly is taken apart and reassembled.
· The Pro-System gauge set (PN # PSY-BGKO1) allows the brake pressures to be recorded accurately by one person.
· Use the gauges to keep a record of front and rear pressures for reference. Record pressures before disassembly and/or working on the system at the track. This way you will always be able to get back to "square one".
The driver's style is always a deciding factor in setting balance. With this system it is always possible to have the car set up to suite the driver.
· Pro-System offers a rebuild and testing service on the cylinders to insure that they are working correctly and are to factory specifications.

RESERVOIRS:
The high quality Brembo reservoirs are machined from solid stock and sized for the calipers used in NASCAR (front - 240cc; rear -l6Occ). A smaller 8Occ reservoir is available for the clutch but must not be used with the brake system. Reservoirs can be mounted directly to the master cylinders or remote with available fittings. The Brembo reservoir is fitted with a bellow in the cap that separates the fluid from the atmosphere while a vent hole in the cap prevents a vacuum developing in the reservoir. Do not puncture this bellow.

If a non-Brembo reservoir is used make sure that its capacity is such that the fluid will be above minimum level after maximum pad and rotor wear have occurred (with fully extended pistons) and that it has a bellows and a vent hole in the cap. The vent hole should be approximately .040" in diameter. Brembo caps and bellows are available for teams fabricating their own reservoirs. Custom fabricated reservoirs should be as tall and narrow as possible. It is important to avoid overfilling the reservoir. Initial heat build up at the start of a race can expand the fluid and cause pressure in the system until pad wear lowers the volume in the reservoir. Pro-System can fabricate reservoirs to your teams design or ours that will meet your requirements when the Brembo unit will not fit.

BRAKE FLUID RECIRCULATORS:
These systems circulate the small volume of fluid that is displaced with each brake application through the brake plumbing to a valve and ultimately back to the caliper. As the pistons retract upon release of the pedal, a volume of hot fluid passes into the pressure-out line where it loses temperature. The incoming fluid, from the pressure-in line, is obviously cooler. Between brake applications the new charge of cooler fluid absorbs heat from the caliper, seals, pistons, etc. With the next application of the pedal the process repeats itself. After a pit stop the pedal can be pumped a few times while going back onto the track to get fresh fluid into the calipers displacing the fluid that was heat soaked during the pit stop. These systems can accurately be called "brake system coolers" as well as recirculators. Their function helps keep the seals cooler allowing the designed amount of "roll-back" to retract the pistons and reduce pad drag, ultimately lowering system temperatures.

Brake fluid recirculators work very well in reducing the effects of fluid boil during a race or pit stop. With a good system, recovery time is minimal. Pro-System recommends two systems. The Stewart Components system (PN # SCO-LCBS) and the Brembo system (PN # BRE-0505510) both work very well and have a successful racing history. Follow the manufactures installation procedure for both systems for trouble free results. Brembo brake systems do not like residual line pressure. Some other brands of recirculator systems have residual line pressure, which will cause brake drag and compromise braking performance. The Brembo and Stewart Components systems do not have residual system pressure.

· The use of any "anti-lock" valve or other in-line hydraulic device will compromise performance and could cause drag.
· Mount the recirculator valve as close to the master cylinders as possible keeping it below the cylinders.
· The best performing brake systems are ones that are kept simple and installed to the manufactures specifications.

BRAKE LINES:
Pro-System offers lines pre-assembled for the Brembo calipers that have been pressure checked and part numbered for a teams specific length and location (i.e. chassis to rear axle housing). These unique part numbers will belong to the team for ordering their own spec lines. The cost is significantly less than buying bulk line and re-usable fittings and doing the assembly in-house while having the added confidence of tested line assemblies.

· It is recommended that rigid lines with an ID of 3/16" be used throughout the chassis because of their resistance to flex.
· AN-3 stainless steel braid Teflon should be used from the chassis out to the calipers and rear axle.
· Flex lines in AN-2 will restrict fluid flow and lines in AN-4 will increase displacement with the possibility of a spongy pedal feel. AN-4 is good for the clutch line.
·Route all lines down hill from the master cylinders and avoid loops that go up in the SS braided lines.

BRAKE FLUID and BLEEDING:
Pro-System recommends Brembo brake fluid for heavy braking tracks. This new fluid has shown to have the highest boiling point and the lowest compressibility of any fluid used in professional racing. Most brake fluids are not compatible with another brand. Mixing fluids or changing brands without thoroughly flushing all lines and components in the car may cause problems. It is our recommendation for safety, simplicity and ease of maintenance that teams choose one fluid and use that brand exclusively.

·New or rebuilt calipers and/or master cylinders are difficult to bleed when empty and can consume a lot of expensive fluid in the process. Pressure or vacuum bleeding these components on the bench before installing on the car can make the job easier, quicker and more thorough.
·When bleeding a system with twin master cylinders, bleed one front and one rear caliper simultaneously in order to allow each master cylinder a full stroke.
· Start with the inside bleed screw and then go to the outside.
·Open the bleed screws and pump the pedal slowly waiting at least 2 seconds between strokes for the master cylinders to refill.
· Fast and hard pumping of the pedal should be avoided as air bubbles can be created through fluid cavitation inside the system.
· Vacuum, pressure, and gravity bleeding all work very well on the car or on the workbench.
· When bleeding is finished hold pressure on the system for 10 seconds while checking for leaks.

COOLING & OVERHEATING:
The very best cooling system design requires that the cross sectional area of the duct be maintained from the opening in the nose to the duct exit at the spindle and for the duct to be as short and straight as possible. In a NASCAR application this is near impossible to achieve with the compromises that must be made. However the closer the system is to that ideal the better the system will cool and the smaller the opening in the nose can be for a given flow. During construction, the brake duct should be the priority over fender bracing that could compromise the airflow or mounting. Build the bracing around the duct not the duct around the bracing. A simple cooling system is often the most effective.

It should be noted that in a test situation with only one car on the track it easy for premature pad wear and/or rotor grooving to occur in a hard 40-lap test run on a to 5/8 mile track. This can happen with the best cooling. Our experience has shown that the same wear rate rarely occurs during the race. You can destroy rotors and pads in 40 laps on a short track if you try. In these cases, an experienced based judgment call is needed between the driver and team regarding the premature wear.

Rotors operating constantly above 11 300-F will grove and pad wear will greatly accelerate. If the red thermal paint is completely burning off the rotor more cooling is needed immediately to avoid a potential failure in the system. The maximum heat soaked temperature that a brake system will see in a race may take 100 laps to develop on a short track. On a road course it can develop in as little as 20 laps.

Increased wear on pads and rotors from overheating plus other temperature related problems could have another source. A driver that rides with his left foot on the brake pedal, and/or uses several brake applications through a turn to set the car, and/or pumps the brakes at the end of a straight can cause this. These drivers are not doing anything wrong but are instead using the brakes to make the car do what they want. The data acquisition system is the best tool for identifying this. Trying different size pedal return springs will sometimes solve the problem but all to often the solution is in providing a better cooling duct system.

· Keep the openings in the nose vertical and as close to the center of the car as possible to be in the area of highest pressure.
· Flow is decreased dramatically by even slightly crushing or bending the 3" flexible duct tubes. Added length also decreases flow.
· The use of the 5" fans is helpful however the 3" fans are inadequate and should not be used.
· When using the 5" fan (PN # DET-758 & DET-754), the 3" inlet section of the fan should be cut off and the lead in trumpet (PN # DET-755) installed. This will dramatically increase the performance of the fan.
·Front or leading mounted calipers for short track/road racing make ducting more effective and easier to design and build (with
the shock in the rear).
· The cooling system should be under constant and never ending development.
· It is much easier to find more air by pulling tape off a well-developed duct system than to be faced with redesigning an inadequate system at the track.
· Never believe that the duct system is as good as it can be.
· You can get more air by simply improving the delivery system to the caliper/rotor without increasing the opening in the nose.
· The high pressure in the radiator duct (in front of the radiator) is a low drag source for air to duct to the brakes. If this air can be used without raising engine temp, it is a good source.
· Pads that are constantly wearing with more than .040" of taper from top to bottom or .020" taper outside to inside indicate that there may be a mounting problem or cooling problem.
· Premature grooving of the rotor or accelerated pad wear in a race condition is a sign of inadequate cooling.
· The pyrometer can be a useful tool if consistency is used in recording temperatures. The same person should read the pyrometer each time, starting as soon as the car stops with the RF wheel and then going to the RR. The right front will be the hottest and will consequently cool initially at a faster rate than the right rear. It is important for the driver to use the same braking procedure exiting the track into the pits in order to have good data. The pyrometer can give unreliable data when used improperly.
· Temp stickers on the calipers are a good tool but must also be read fast when testing. If the car comes into the pits with extremely hot rotors, the heat will migrate into the caliper after the car stops. After a few seconds the sticker will give a reading reflecting the heat soaked temp and not the on track temp. This is a useful tool to tell the highest temperature the caliper reached during a race and pit stops.
· The use of rotor paint is a better tool to measure temperature. The green goes off at 806o~F the orange at 1 0400-F and the red at 11 300-F The thermal paints reflect on track temperature, as the temperature must remain at or above a level for a period of time for the color to go off. They will not change in the pits.
· By far the best tool for looking at brake temps is the data acquisition system that most teams now use in testing. Pro-System offers inexpensive thermocouples that are designed to run inside the pads near the rotor/pad interface and others that can be attached to the calipers. Contact thermocouples are available to run against the rotors. The use of these devices is the best way to record brake temperatures and is very useful in developing ducting. This system will show temps on the track and also the rate at which the temps migrate into other components. If the cooling system is verified to be adequate by using these tools during a hard test, the team can go to the race with confidence that they will not have brake-cooling problems.