Other/Misc: How to : Bed-In Your New Brakes
01-07-2012, 09:29 PM
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How to : Bed-In Your New Brakes
How to Bed-In your new brakes.
Bedding allows your brakes to reach their full potential. Until they are bedded, your brakes simply do not work as well as they can. If you've installed a big brake kit, changed your pads and rotors, or even purchased a brand new car, you should set aside time to bed the brakes according to the instructions below. Proper bedding improves pedal feel, reduces or eliminates brake squeal, prevents (and often cures) brake judder, reduces brake dust, and extends the life of your pads and rotors. For more details on the theory of bedding, please refer to this article by Centric Parts: Pad and Rotor Bed-In Theory, Definitions and Procedures
Caution Immediately after installing new pads, rotors or a big brake kit, the first few applications of the brakes will result in very little braking power. Gently use the brakes a few times at low speed in order to build up some grip before blasting down the road at high speed. Otherwise, you may be in for a nasty surprise the first time you hit the brakes at 60 mph.
If you have just installed rotors with zinc or cadmium plating, or if the rotors have an anti-corrosion phosphate coating, you should postpone the bedding process until normal driving has allowed your brake pads to polish the rotors clean and removed all traces of the plating or coating. If your new brake rotors have an oily anti-corrosion coating, you should clean this off thoroughly with brake cleaning spray and/or hot soapy water.
Read and understand these bedding instructions completely before starting. If you have questions, give us a call or email. Do not substitute higher speeds for the 60mph called for in these instructions. The heat in your brakes goes up exponentially as you increase the speed from which you brake. If you make repeated stops from 80 or 90mph with street pads, you will overheat the brakes and may end up having to replace pads and/or rotors.
When following these instructions, avoid other vehicles. Bedding is often best done early in the morning, when traffic is light, since other drivers will have no idea what you are up to and may respond in a variety of ways ranging from fear to curiosity to aggression. A police officer will probably not understand when you try to explain why you were driving erratically! Zeckhausen Racing does not endorse speeding on public roads and takes no responsibility for any injuries or tickets you may receive while following these instructions. Use common sense!
From 60mph, gently apply the brakes a couple of times to bring them up to operating temperature. This prevents you from thermally shocking the rotors and pads in the next steps.
Make eight to ten near-stops from 60mph to about 10-15 mph. Do it HARD by pressing the brakes firmly, but do not lock the wheels or engage ABS. At the end of each slowdown, immediately accelerate back to 60mph and then apply the brakes again. DO NOT COME TO A COMPLETE STOP! If you stop completely and sit with your foot on the brake pedal, you will imprint pad material onto the hot rotors, which could lead to vibration and uneven braking.
The brakes may begin to fade after the 7th or 8th near-stop. This fade will stabilize, but not completely go away until the brakes have fully cooled. A strong smell from the brakes, and even some smoke, is normal.
After the last near-stop, accelerate back up to speed and cruise for a while, using the brakes as little as possible. The brakes need only a few minutes to cool down. Try not to become trapped in traffic or come to a complete stop while the brakes are still very hot.
If full race pads, such as Hawk DTC-70 or Performance Friction PFC01 are being used, add four near-stops from 80 to 10 mph.
After the break-in cycle, there should be a slight blue tint and a light gray film on the rotor face. The blue tint tells you the rotor has reached break-in temperature and the gray film is pad material starting to transfer onto the rotor face. This is what you are looking for. The best braking occurs when there is an even layer of of pad material deposited across the rotors. This minimizes squealing, increases braking torque, and maximizes pad and rotor life.
After the first break in cycle shown above, the brakes may still not be fully broken in. A second bed-in cycle, AFTER the brakes have cooled down fully from the first cycle, may be necessary before the brakes really start to perform well. This is especially true if you have installed new pads on old rotors, since the pads need time to conform to the old rotor wear pattern. If you've just installed a big brake kit, the pedal travel may not feel as firm as you expected. After the second cycle, the pedal will become noticeably firmer. If necessary, bleed the brakes to improve pedal firmness.
Brake Decisions: Breaking in new Brakes - YouTube
================================================== ===========================================
Why bleed brakes?
Fresh brake fluid has a significantly higher boiling point than old fluid, allowing harder braking without fade. This is because brake fluid is hygroscopic and readily absorbs moisture. The more moisture in the fluid, the lower the boiling point.
That same moisture promotes corrosion. Frequent bleeding with fresh fluid allows brake components to last longer. A well maintained brake system can help you avoid ever having to replace calipers, master cylinder or an expensive ABS control unit.
The bleeding process, done properly, removes air bubbles from the hydraulic system, resulting in firmer brake pedal feel and more linear, responsive braking performance. Too much air in the system can be dangerous and result in the pedal sinking to the floor. Air is compressible, brake fluid is not.
How much brake fluid is required?
It is usually possible to bleed all four corners of the car with somewhere between 1/2 and one liter of brake fluid. If you've just installed new brake lines or a big brake kit, it may require more fluid, especially if you are a novice at bleeding.
Must brakes be bled in a specific order?
Bleeding is done one wheel at a time. The "old timers" will tell you to start with the wheel furthest from the master cylinder and work your way closer. Typically, this would mean RR, LR, RF, then LF. However, it doesn't really matter if you start with the front or rear wheels, since they are on separate circuits on modern cars with ABS and/or dynamic stability control systems.
How are brakes bled?
There are many techniques for bleeding brakes and lots of gadgets to make the job easier. For simply replacing old fluid with new, many of these techniques work fine. But for removing air bubbles from the system, one approach is superior. That is the "old fashioned method", which requires an assistant to push on the brake pedal while the mechanic opens and closes the bleed valve on the calipers. This 2-person method generates a sufficient jolt to the brake fluid to knock loose pesky bubbles and allows them to be flushed away. By following these instructions, you will be more likely to end up with a firm brake pedal, often with better feel than the day your car rolled off the assembly line.
1. Block a front wheel with a piece of wood to prevent the car from rolling. Raise the back of the car with a floor jack and then lower it onto a pair of jackstands.
2. Remove the rear wheels.
3. Open the brake fluid reservoir and remove as much old brake fluid as possible, using a suction tool or a turkey baster. Be careful not to spill any fluid, as it will dissolve the paint on your car.
4. Fill the brake reservoir to the top with fresh fluid.
5. Place a box end wrench over the bleed screw on the right rear caliper. Push a clear plastic tube over the nipple on the bleed screw and place the opposite end into a catch bottle. Auto parts stores sell nice catch bottles with a cover that prevents fluid from spilling if it tips over, a 1-way check valve in the cap, and a rubber fitting on the caliper end of the plastic line that snaps in place over a wide range of bleed screw nipple sizes.
6. Tell your assistant to pump the brake pedal a few times until it becomes firm. This is especially important if you have just replaced pads. If you've installed new stainless braided brake lines or installed a big brake kit, there may be enough air in the system that the brake pedal will not get firm. That's OK. Just move on to the next step.
7. Tap the caliper a few times with a rubber mallet or "dead-blow" hammer. This helps to knock loose air bubbles that may be clinging to inside surfaces of the caliper.
8. Have your assistant PUSH hard on the brake pedal and HOLD. With a quick motion, open the bleed screw about 1/4 turn. Fluid (and probably a few air bubbles) will flow through the plastic tube and into the catch bottle. A light placed behind the tube will make it easier to see what is coming out of the caliper.
9. Close the bleed screw just before the brake pedal reaches the floor. Don't worry if the timing is off at first. You will quickly figure it out with feedback from your assistant.
10. Tell your assistant to RELEASE.
11. Repeat steps 8 - 10. Do this about 6 times and then go to the front of the car to check the fluid level. You MUST NOT allow the level to fall to the point where you suck air into the master cylinder.
12. Top off the brake fluid level and continue for a total of about 10 pumps or until you no longer see any air bubbles coming out of the caliper.
13. Repeat the process for the other rear caliper.
14. Make sure both calipers are wiped clean of brake fluid and that none has spilled on the rotors or pads. Use brake cleaning spray if necessary. Reinstall the rear wheels and torque to factory specification, then lower car to the ground.
15. Now apply the parking brake, put the car in gear (or PARK) and raise the front of the car with your floor jack. Lower it onto a pair of jackstands.
16. Remove the front wheels.
17. Follow the exact same technique as with the rear wheels, starting with the passenger side caliper. The fluid will flow more rapidly out of the front calipers, so you will need to check the level in the brake fluid reservoir more frequently to avoid letting it drop too low.
18. Reinstall and torque the front wheels, then lower the car to the ground.
19. Top off the brake fluid reservoir and replace the cap.
================================================== ======================================
Pad and Rotor Bed-In Theory, Definitions and Procedures
http://www.centricparts.com/files/Ce...n%20Theory.pdf
Source - Instructions for bedding in your brakes
-Scott
Bedding allows your brakes to reach their full potential. Until they are bedded, your brakes simply do not work as well as they can. If you've installed a big brake kit, changed your pads and rotors, or even purchased a brand new car, you should set aside time to bed the brakes according to the instructions below. Proper bedding improves pedal feel, reduces or eliminates brake squeal, prevents (and often cures) brake judder, reduces brake dust, and extends the life of your pads and rotors. For more details on the theory of bedding, please refer to this article by Centric Parts: Pad and Rotor Bed-In Theory, Definitions and Procedures
Caution Immediately after installing new pads, rotors or a big brake kit, the first few applications of the brakes will result in very little braking power. Gently use the brakes a few times at low speed in order to build up some grip before blasting down the road at high speed. Otherwise, you may be in for a nasty surprise the first time you hit the brakes at 60 mph.
If you have just installed rotors with zinc or cadmium plating, or if the rotors have an anti-corrosion phosphate coating, you should postpone the bedding process until normal driving has allowed your brake pads to polish the rotors clean and removed all traces of the plating or coating. If your new brake rotors have an oily anti-corrosion coating, you should clean this off thoroughly with brake cleaning spray and/or hot soapy water.
Read and understand these bedding instructions completely before starting. If you have questions, give us a call or email. Do not substitute higher speeds for the 60mph called for in these instructions. The heat in your brakes goes up exponentially as you increase the speed from which you brake. If you make repeated stops from 80 or 90mph with street pads, you will overheat the brakes and may end up having to replace pads and/or rotors.
When following these instructions, avoid other vehicles. Bedding is often best done early in the morning, when traffic is light, since other drivers will have no idea what you are up to and may respond in a variety of ways ranging from fear to curiosity to aggression. A police officer will probably not understand when you try to explain why you were driving erratically! Zeckhausen Racing does not endorse speeding on public roads and takes no responsibility for any injuries or tickets you may receive while following these instructions. Use common sense!
From 60mph, gently apply the brakes a couple of times to bring them up to operating temperature. This prevents you from thermally shocking the rotors and pads in the next steps.
Make eight to ten near-stops from 60mph to about 10-15 mph. Do it HARD by pressing the brakes firmly, but do not lock the wheels or engage ABS. At the end of each slowdown, immediately accelerate back to 60mph and then apply the brakes again. DO NOT COME TO A COMPLETE STOP! If you stop completely and sit with your foot on the brake pedal, you will imprint pad material onto the hot rotors, which could lead to vibration and uneven braking.
The brakes may begin to fade after the 7th or 8th near-stop. This fade will stabilize, but not completely go away until the brakes have fully cooled. A strong smell from the brakes, and even some smoke, is normal.
After the last near-stop, accelerate back up to speed and cruise for a while, using the brakes as little as possible. The brakes need only a few minutes to cool down. Try not to become trapped in traffic or come to a complete stop while the brakes are still very hot.
If full race pads, such as Hawk DTC-70 or Performance Friction PFC01 are being used, add four near-stops from 80 to 10 mph.
After the break-in cycle, there should be a slight blue tint and a light gray film on the rotor face. The blue tint tells you the rotor has reached break-in temperature and the gray film is pad material starting to transfer onto the rotor face. This is what you are looking for. The best braking occurs when there is an even layer of of pad material deposited across the rotors. This minimizes squealing, increases braking torque, and maximizes pad and rotor life.
After the first break in cycle shown above, the brakes may still not be fully broken in. A second bed-in cycle, AFTER the brakes have cooled down fully from the first cycle, may be necessary before the brakes really start to perform well. This is especially true if you have installed new pads on old rotors, since the pads need time to conform to the old rotor wear pattern. If you've just installed a big brake kit, the pedal travel may not feel as firm as you expected. After the second cycle, the pedal will become noticeably firmer. If necessary, bleed the brakes to improve pedal firmness.
Brake Decisions: Breaking in new Brakes - YouTube
================================================== ===========================================
Why bleed brakes?
Fresh brake fluid has a significantly higher boiling point than old fluid, allowing harder braking without fade. This is because brake fluid is hygroscopic and readily absorbs moisture. The more moisture in the fluid, the lower the boiling point.
That same moisture promotes corrosion. Frequent bleeding with fresh fluid allows brake components to last longer. A well maintained brake system can help you avoid ever having to replace calipers, master cylinder or an expensive ABS control unit.
The bleeding process, done properly, removes air bubbles from the hydraulic system, resulting in firmer brake pedal feel and more linear, responsive braking performance. Too much air in the system can be dangerous and result in the pedal sinking to the floor. Air is compressible, brake fluid is not.
How much brake fluid is required?
It is usually possible to bleed all four corners of the car with somewhere between 1/2 and one liter of brake fluid. If you've just installed new brake lines or a big brake kit, it may require more fluid, especially if you are a novice at bleeding.
Must brakes be bled in a specific order?
Bleeding is done one wheel at a time. The "old timers" will tell you to start with the wheel furthest from the master cylinder and work your way closer. Typically, this would mean RR, LR, RF, then LF. However, it doesn't really matter if you start with the front or rear wheels, since they are on separate circuits on modern cars with ABS and/or dynamic stability control systems.
How are brakes bled?
There are many techniques for bleeding brakes and lots of gadgets to make the job easier. For simply replacing old fluid with new, many of these techniques work fine. But for removing air bubbles from the system, one approach is superior. That is the "old fashioned method", which requires an assistant to push on the brake pedal while the mechanic opens and closes the bleed valve on the calipers. This 2-person method generates a sufficient jolt to the brake fluid to knock loose pesky bubbles and allows them to be flushed away. By following these instructions, you will be more likely to end up with a firm brake pedal, often with better feel than the day your car rolled off the assembly line.
1. Block a front wheel with a piece of wood to prevent the car from rolling. Raise the back of the car with a floor jack and then lower it onto a pair of jackstands.
2. Remove the rear wheels.
3. Open the brake fluid reservoir and remove as much old brake fluid as possible, using a suction tool or a turkey baster. Be careful not to spill any fluid, as it will dissolve the paint on your car.
4. Fill the brake reservoir to the top with fresh fluid.
5. Place a box end wrench over the bleed screw on the right rear caliper. Push a clear plastic tube over the nipple on the bleed screw and place the opposite end into a catch bottle. Auto parts stores sell nice catch bottles with a cover that prevents fluid from spilling if it tips over, a 1-way check valve in the cap, and a rubber fitting on the caliper end of the plastic line that snaps in place over a wide range of bleed screw nipple sizes.
6. Tell your assistant to pump the brake pedal a few times until it becomes firm. This is especially important if you have just replaced pads. If you've installed new stainless braided brake lines or installed a big brake kit, there may be enough air in the system that the brake pedal will not get firm. That's OK. Just move on to the next step.
7. Tap the caliper a few times with a rubber mallet or "dead-blow" hammer. This helps to knock loose air bubbles that may be clinging to inside surfaces of the caliper.
8. Have your assistant PUSH hard on the brake pedal and HOLD. With a quick motion, open the bleed screw about 1/4 turn. Fluid (and probably a few air bubbles) will flow through the plastic tube and into the catch bottle. A light placed behind the tube will make it easier to see what is coming out of the caliper.
9. Close the bleed screw just before the brake pedal reaches the floor. Don't worry if the timing is off at first. You will quickly figure it out with feedback from your assistant.
10. Tell your assistant to RELEASE.
11. Repeat steps 8 - 10. Do this about 6 times and then go to the front of the car to check the fluid level. You MUST NOT allow the level to fall to the point where you suck air into the master cylinder.
12. Top off the brake fluid level and continue for a total of about 10 pumps or until you no longer see any air bubbles coming out of the caliper.
13. Repeat the process for the other rear caliper.
14. Make sure both calipers are wiped clean of brake fluid and that none has spilled on the rotors or pads. Use brake cleaning spray if necessary. Reinstall the rear wheels and torque to factory specification, then lower car to the ground.
15. Now apply the parking brake, put the car in gear (or PARK) and raise the front of the car with your floor jack. Lower it onto a pair of jackstands.
16. Remove the front wheels.
17. Follow the exact same technique as with the rear wheels, starting with the passenger side caliper. The fluid will flow more rapidly out of the front calipers, so you will need to check the level in the brake fluid reservoir more frequently to avoid letting it drop too low.
18. Reinstall and torque the front wheels, then lower the car to the ground.
19. Top off the brake fluid reservoir and replace the cap.
================================================== ======================================
Pad and Rotor Bed-In Theory, Definitions and Procedures
http://www.centricparts.com/files/Ce...n%20Theory.pdf
Source - Instructions for bedding in your brakes
-Scott
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