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Brake Pads
- Thread starter Roger Reid
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- Performance Roadster
The recommended procedure varies depending on the manufacturer. Usually the recommended procedure is printed on the box. Here are some examples for various manufacturers:
Brake Tech - Brake Pad and Rotor Bed-In Procedures
For Carbotech in particular, here's there FAQ page:
Carbotech Performance Brakes: Frequently Asked Questions
wiztecy
Active Member
I just called Carbotech regards the AX6 Autocross vs. the Bobcat street pad. The guy was great, friendly, and helpful.
I asked a few questions, first I asked if the AX6 would have better bite than the Bobcat. He said by far it does, he also indicated to make sure you and your passenger has their seat belts fastened for that it will throw you forward for that the grip is that good. They specifically designed this pad to bite well over the bobcat. They put the dust and noise aside and designed it for hard stops.
Second question was its working temperature. Carbotech states that the AX6 works great down to 55 degrees Fahrenheit. The person I spoke to says it actually works very well all the way down to 0 degrees Fahrenheit. So that's good for people in cold weather climates.
Lastly I asked if the AX6 pads need to warm up in order to work and achieve their bite over the Bobcat pads. He said the AX6 pads don't need to be heated up in order to bite and to be effective, so they'll work great for a daily commuter and this is how my roadster's being used.
Still waiting on my pads which I ordered from an online store. If you do order them you may be better to order them from Carbotech directly. You can mention that there's a discussion supporting their pads on this forum, I heard they'll offer 7% off your order if you do (from reading other forums).
The part number listed in the picture a few threads before this one is correct for both the front and back, the Carbotech read me the part numbers just to confirm.
If you have any questions don't hesitate to call Carbotech!
I asked a few questions, first I asked if the AX6 would have better bite than the Bobcat. He said by far it does, he also indicated to make sure you and your passenger has their seat belts fastened for that it will throw you forward for that the grip is that good. They specifically designed this pad to bite well over the bobcat. They put the dust and noise aside and designed it for hard stops.
Second question was its working temperature. Carbotech states that the AX6 works great down to 55 degrees Fahrenheit. The person I spoke to says it actually works very well all the way down to 0 degrees Fahrenheit. So that's good for people in cold weather climates.
Lastly I asked if the AX6 pads need to warm up in order to work and achieve their bite over the Bobcat pads. He said the AX6 pads don't need to be heated up in order to bite and to be effective, so they'll work great for a daily commuter and this is how my roadster's being used.
Still waiting on my pads which I ordered from an online store. If you do order them you may be better to order them from Carbotech directly. You can mention that there's a discussion supporting their pads on this forum, I heard they'll offer 7% off your order if you do (from reading other forums).
The part number listed in the picture a few threads before this one is correct for both the front and back, the Carbotech read me the part numbers just to confirm.
If you have any questions don't hesitate to call Carbotech!
wiztecy
Active Member
Yes, I'll be putting them on myself and pulling the rotors off to have them resurfaced at the local speed shop.
wiztecy
Active Member
So I changed out the right side of my Roadster with Carbotech AX6 pads. Have to wait in the morning to have the left side rotors turned on the car. Shop tech went home who cuts the rotors... Brake job was really easy, just take your time, buy 1 can of brake clean for each wheel and also take the time to spray down the wheels and calipers with brake clean.
A couple of tips:
Buy a can of brake squeal quieter spray. Its basically a sticky compound, this gets applied to the backs of the brake pads as well as the contacts the pads make with the piston and caliper. Don't put this on anything that slides. It is to mute any shake of the pad that causes the squeal I used CRC Disk Brake Quiet:
Amazon.com: CRC Industries 05017 Disc Brake Quiet - 12 oz.: Automotive
Also buy some good corrosion resistant grease, this gets applied to the moving parts... I had some left over from a previous brake job. You want to apply this to any sliding part such as the brake and caliper contacts as well as the pins that hold the pads on. Use your best judgement where it goes and don't over apply. The goal is to prevent corrosion and rust and allow things to slide nicely, you don't want dirt and grit to get trapped in the grease which occurs if there's too much.
One major observation I made is that I strongly believe the rotors on my Roadster were installed backwards, meaning the vents on the rotors are not scooping air to cool the rotors down but rather deflecting the air. I looked at the Video on the beginning of this thread as an aid to remove my pads and looking at the Lotus rotor, it is facing in the right direction, where it scoops air to cool the rotor and blow dust out.... I'll be flipping my rotors around tomorrow... I know they're not installed right. You may want to check your roadster.
Another Tip:
Our rotors are drilled to help cool and remove rust, dust, and dirt. Talking shop at my local speed shop the tech noted that one guy re-countersinks the rotor holes. It actually makes sense, but you don't want to drill metal out. You want to clean the hole from dirt and debris as well as cleaning the countersink. Our rotors have a countersink drilled into their surface to help scoop out the dirt and dust. This gets filled with dirt and goop.... same with the holes that's drilled through our rotors. I found that 70% of my drilled holes where filled with goop and dust. So I used a drill bit that was the same size/smaller to bore out the hole and clean it out. I also cleaned out the countersink as well. Note, I ran the drill backwards to prevent from cutting out any metal from the rotor. I actually hosed the rotor with water before, during, and after this process to help take away the dust and dirt. You want to hit the cooling fins to clean them out too. There's dust, cobb webs and all types of crap in there that needs to be cleaned. I then hit the rotor and its cooling fins as well as hitting each drilled hole in the rotor with brake clean. Its good to do this before having your rotor cut down. When you get your rotors back from the shop, hit them with brake clean again.
A note from my speed shop. My front rotors were slightly warped. So that means there's an issue with the braking on the front of my roadster... if its heating the rotors so much to warp its not cooling and its working too hard. Possibly flipping the rotors around so they actually cool down will fix this. I'll see if the Carbotech pads will fix this in combination. I'll also be keeping an eye on the brake dust that's logged in the drilled rotor holes and re-purge them out if necessary around 5k miles. My roadster now has 9k miles and as you can see needed maintenance in order to have optimum braking capabilities.
Lastly my speed shop tech commented that you should always re-surface your rotors when you have new pads installed. Reason being is that the rotor needs to have a nice rough / fresh surface to burn off the break in material that's typically applied to the face of the pads. It makes sense. Looking at my nicely re-surfaced rotor it has a slight rough surface to it. A rotor that hasn't been resurfaced has a glaze or polished look. Lastly if I didn't have my rotors resurfaced I wouldn't have known that the front's were warped.
A couple of tips:
Buy a can of brake squeal quieter spray. Its basically a sticky compound, this gets applied to the backs of the brake pads as well as the contacts the pads make with the piston and caliper. Don't put this on anything that slides. It is to mute any shake of the pad that causes the squeal I used CRC Disk Brake Quiet:
Amazon.com: CRC Industries 05017 Disc Brake Quiet - 12 oz.: Automotive
Also buy some good corrosion resistant grease, this gets applied to the moving parts... I had some left over from a previous brake job. You want to apply this to any sliding part such as the brake and caliper contacts as well as the pins that hold the pads on. Use your best judgement where it goes and don't over apply. The goal is to prevent corrosion and rust and allow things to slide nicely, you don't want dirt and grit to get trapped in the grease which occurs if there's too much.
One major observation I made is that I strongly believe the rotors on my Roadster were installed backwards, meaning the vents on the rotors are not scooping air to cool the rotors down but rather deflecting the air. I looked at the Video on the beginning of this thread as an aid to remove my pads and looking at the Lotus rotor, it is facing in the right direction, where it scoops air to cool the rotor and blow dust out.... I'll be flipping my rotors around tomorrow... I know they're not installed right. You may want to check your roadster.
Another Tip:
Our rotors are drilled to help cool and remove rust, dust, and dirt. Talking shop at my local speed shop the tech noted that one guy re-countersinks the rotor holes. It actually makes sense, but you don't want to drill metal out. You want to clean the hole from dirt and debris as well as cleaning the countersink. Our rotors have a countersink drilled into their surface to help scoop out the dirt and dust. This gets filled with dirt and goop.... same with the holes that's drilled through our rotors. I found that 70% of my drilled holes where filled with goop and dust. So I used a drill bit that was the same size/smaller to bore out the hole and clean it out. I also cleaned out the countersink as well. Note, I ran the drill backwards to prevent from cutting out any metal from the rotor. I actually hosed the rotor with water before, during, and after this process to help take away the dust and dirt. You want to hit the cooling fins to clean them out too. There's dust, cobb webs and all types of crap in there that needs to be cleaned. I then hit the rotor and its cooling fins as well as hitting each drilled hole in the rotor with brake clean. Its good to do this before having your rotor cut down. When you get your rotors back from the shop, hit them with brake clean again.
A note from my speed shop. My front rotors were slightly warped. So that means there's an issue with the braking on the front of my roadster... if its heating the rotors so much to warp its not cooling and its working too hard. Possibly flipping the rotors around so they actually cool down will fix this. I'll see if the Carbotech pads will fix this in combination. I'll also be keeping an eye on the brake dust that's logged in the drilled rotor holes and re-purge them out if necessary around 5k miles. My roadster now has 9k miles and as you can see needed maintenance in order to have optimum braking capabilities.
Lastly my speed shop tech commented that you should always re-surface your rotors when you have new pads installed. Reason being is that the rotor needs to have a nice rough / fresh surface to burn off the break in material that's typically applied to the face of the pads. It makes sense. Looking at my nicely re-surfaced rotor it has a slight rough surface to it. A rotor that hasn't been resurfaced has a glaze or polished look. Lastly if I didn't have my rotors resurfaced I wouldn't have known that the front's were warped.
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frequencydip
Sig 100 - #52
@wiztecy
Thats very odd that your rotors would be warped, do you track the car? Rotors really only warp when reaching very high temperatures 700+ degree F. Also odd that the rotors were installed backwards, I checked mine and they are correct. The directional vanes should point towards the back of the car. They pull air in from the center and expel air outward.
Also drilled rotors serve no purpose in todays cars. All they do is act as cheese graters and wear down our pads faster. Drilled rotors were needed in the 40s and 50s when brake pads were prone to off gassing and glazing. Today they are purely aesthetic in value, although some claim reduced weigh (this is negligible), and others cite improved stopping performance in wet conditions also negligible. I would prefer a solid rotor if the option existed, it provides more surface area for pad contact, reduces pad wear, and improves thermal capacity of the rotor.
Thats very odd that your rotors would be warped, do you track the car? Rotors really only warp when reaching very high temperatures 700+ degree F. Also odd that the rotors were installed backwards, I checked mine and they are correct. The directional vanes should point towards the back of the car. They pull air in from the center and expel air outward.
Also drilled rotors serve no purpose in todays cars. All they do is act as cheese graters and wear down our pads faster. Drilled rotors were needed in the 40s and 50s when brake pads were prone to off gassing and glazing. Today they are purely aesthetic in value, although some claim reduced weigh (this is negligible), and others cite improved stopping performance in wet conditions also negligible. I would prefer a solid rotor if the option existed, it provides more surface area for pad contact, reduces pad wear, and improves thermal capacity of the rotor.
wiztecy
Active Member
Frequencydip, when you say your directional vanes point towards the back of the car, what is your reference, the top or bottom of the rotor?
It was odd that my rotor was slightly warped too, I don't track the car nor did the owner who had it before me. Car doesn't have all that many miles on it really and brakes were not heavily used in my opinion. (3,800 miles when I bought it, 9k now).
As for the drilled rotors, I don't like them either. They're proned to cracking under heavy use. I prefer slotted over both full or drilled. The slots allow heat / off gassing and a place for brake dust and rust to slide into where it has a chance to blow away. I do think the holes are doing something, they're definitely catching the dirt and grime. As for heat and transferring that, I'm not so sure... But I do think its good to clean these holes out so that grime does not get on your new and improved brake pads and nice rotor surface. One thing I know for sure about brake jobs, you have to be clean like a doctor. Granted I've done brakes without cleaning anything but I really do love my roadster and I know she needs all the love in this area.
I'm reviewing the video of the Lotus brake change. It appears to me, still looking, that the front pad change (reference top of the rotor) that the vanes are facing backwards. If I look at the rear brake change, (reference top rotor) the vanes are facing front. Honestly I'm not adding any Irish Creme in my coffee (just yet
)
Here's the video:
http://www.youtube.com/watch?v=d2jVE1I6aBs
Front Vane view: @ 0:39
(working on front left brake/rotor)
Appears vanes are facing towards the back, reference top of rotor
Rear Vane view: @ 1:32
(Appears to be working on rear right brake/rotor)
Appears vanes are facing towards the front, reference top of rotor
It was odd that my rotor was slightly warped too, I don't track the car nor did the owner who had it before me. Car doesn't have all that many miles on it really and brakes were not heavily used in my opinion. (3,800 miles when I bought it, 9k now).
As for the drilled rotors, I don't like them either. They're proned to cracking under heavy use. I prefer slotted over both full or drilled. The slots allow heat / off gassing and a place for brake dust and rust to slide into where it has a chance to blow away. I do think the holes are doing something, they're definitely catching the dirt and grime. As for heat and transferring that, I'm not so sure... But I do think its good to clean these holes out so that grime does not get on your new and improved brake pads and nice rotor surface. One thing I know for sure about brake jobs, you have to be clean like a doctor. Granted I've done brakes without cleaning anything but I really do love my roadster and I know she needs all the love in this area.
I'm reviewing the video of the Lotus brake change. It appears to me, still looking, that the front pad change (reference top of the rotor) that the vanes are facing backwards. If I look at the rear brake change, (reference top rotor) the vanes are facing front. Honestly I'm not adding any Irish Creme in my coffee (just yet
)Here's the video:
http://www.youtube.com/watch?v=d2jVE1I6aBs
Front Vane view: @ 0:39
(working on front left brake/rotor)
Appears vanes are facing towards the back, reference top of rotor
Rear Vane view: @ 1:32
(Appears to be working on rear right brake/rotor)
Appears vanes are facing towards the front, reference top of rotor
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wiztecy
Active Member
Thanks frequencydip for the mental note, makes sense now!
"The directional vanes should point towards the back of the car. They pull air in from the center and expel air outward."
"The directional vanes should point towards the back of the car. They pull air in from the center and expel air outward."
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wiztecy
Active Member
"Improper wheel torquing can also warp the rotors. "
Interesting, on the net it seems like it can go either way. I can see the point of when the rotor heats up it needs to shift/move and thus if its overtorqued could prevent this and warp a rotor. I do have to say the front did seem overtightend compared to the rear. It had that sketchy snap sound when I backed them all off. Granted that if the rotors heated up this may cause the same effect as well as the lug nuts tightening down from the heating / cooling effect on them.
Interesting, on the net it seems like it can go either way. I can see the point of when the rotor heats up it needs to shift/move and thus if its overtorqued could prevent this and warp a rotor. I do have to say the front did seem overtightend compared to the rear. It had that sketchy snap sound when I backed them all off. Granted that if the rotors heated up this may cause the same effect as well as the lug nuts tightening down from the heating / cooling effect on them.
Based on inspecting a whole lot of tires and determining the causes of odd wear, warped rotors from improper/uneven torque are common. Note that the smaller the rotor assembly is the more likely it is that torque will have an effect. Of course, any heat will exacerbate the warping.
frequencydip
Sig 100 - #52
off the top of the rotor, here is a pic I found showing the directional vanes
The gunk you see getting built up in the drilled holes is because the holes themselves cause the pad to shave as it passes over the hole. Slotted rotors are not as bad as cross drilled in shaving the pad and have some advantages with steel rotors in racing only applications. At extremely high speeds brake pads can glaze due to the immense heat of braking at speeds well over 100MPH brakes will hit temperatures of 1000 to 1300 F. This is not an issue anymore for todays race cars such as the solid carbon fiber brakes F1 uses.
wiztecy
Active Member
Another tip, whey you spray down your rear calipers (even the fronts) cover anything that will get overspray that's plastic or has paint. I just noticed the tips of my rear airdam have sight splatter marks from the brake clean. Can't get it off there now, cover it as a precaution.
When removing the springs off the brakes/calipers take a picture and take note how they're placed in there. They can be installed incorrectly, I did with one and had to map to the untouched wheel to understand how its properly pre-loaded.
Make sure that the rear pin that holds the brake pads is fully tapped in. The head should not be recessed but rather should drop into caliper some. The retaining spring at the end of the pin needs to compress and lock.
If you find an extra washer laying around after removing the rear caliper, it goes to the 15mm upper bolt that mounts the caliper to the wheel hub assembly.
Also torque your wheel lug nuts to: 77 ft/lbs of torque
Does anyone have the brake caliper bolt torque specs? This would be a good place to place them to make this thread more complete. Should be the same as a Lotus Elise.
I also just got back from bedding in the resurfaced rotors and the brake pads. Huge improvement over stock and happy with the performance. I can make the front of the car compress and have the front-end dive and lock the suspension down. I really couldn't get that feel from the stocks. This is good, more weight over the front wheels to stop. Secondly on smooth pavement when hard breaking I can hear a slight constant squeal coming from the tires, especially the fronts. This is also good, the ABS is working well with the brakes.
I'm pleased with the upgrade.
My machine shop found two rotors that were warped. That in itself will improve braking. So the entire brake exercise has paid off in making my Roadster safer and give me the ability to handle unexpected emergencies that may pop in front of me. One place I really need this margin is the dang car-pool lane. Its crazy passing on-ramps and when an ICE vehicle just busts into your lane... Lanes that go 45-70 near stopped cars by your side doesn't make sense in my opinion. I like the benefit though
When removing the springs off the brakes/calipers take a picture and take note how they're placed in there. They can be installed incorrectly, I did with one and had to map to the untouched wheel to understand how its properly pre-loaded.
Make sure that the rear pin that holds the brake pads is fully tapped in. The head should not be recessed but rather should drop into caliper some. The retaining spring at the end of the pin needs to compress and lock.
If you find an extra washer laying around after removing the rear caliper, it goes to the 15mm upper bolt that mounts the caliper to the wheel hub assembly.
Also torque your wheel lug nuts to: 77 ft/lbs of torque
Does anyone have the brake caliper bolt torque specs? This would be a good place to place them to make this thread more complete. Should be the same as a Lotus Elise.
I also just got back from bedding in the resurfaced rotors and the brake pads. Huge improvement over stock and happy with the performance. I can make the front of the car compress and have the front-end dive and lock the suspension down. I really couldn't get that feel from the stocks. This is good, more weight over the front wheels to stop. Secondly on smooth pavement when hard breaking I can hear a slight constant squeal coming from the tires, especially the fronts. This is also good, the ABS is working well with the brakes.
I'm pleased with the upgrade.
My machine shop found two rotors that were warped. That in itself will improve braking. So the entire brake exercise has paid off in making my Roadster safer and give me the ability to handle unexpected emergencies that may pop in front of me. One place I really need this margin is the dang car-pool lane. Its crazy passing on-ramps and when an ICE vehicle just busts into your lane... Lanes that go 45-70 near stopped cars by your side doesn't make sense in my opinion. I like the benefit though
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wiztecy
Active Member
Pics for reference. Shiny Rotors are resurfaced and you can see the countersink in the drilled rotors. Picture of the front dirty/dusty caliper is to show the preloaded spring and its orientation. Arrow faces up. The arrow is pointing to the part of the spring that needs to go *under* the upper pin. This can be installed wrong so look at this pic and compare to your setup. I also have a pic of the rear Caliper with the new brake pads as well as the silver upper bolt that holds the rear caliper on. The black Allen bolt goes to the lower portion of the caliper whereas the silver hex bolt with washer goes to the upper caliper mounting hole.
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strider
Active Member
Thanks for this wiztecy! My pads arrive tomorrow so one of these weekends I'll be tackling this project. Should bleed the brakes while I'm in there since it's been almost 2 years now.
wiztecy
Active Member
If you're not seeing cloudiness in the brake fluid reservoir why bleed your brakes? There's no contamination of water if its not cloudy. I'd concentrate on the pads and down the road bleed the fluid in a separate process.
I'm also not experiencing any squeals from the AX6 pads at all so their working nice on the street so far.
I'm also not experiencing any squeals from the AX6 pads at all so their working nice on the street so far.
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frequencydip
Sig 100 - #52
I would highly recommend performing a brake fluid flush, use some high quality fluid such as ATE Super Blue Amazon.com: ATE 706302 Original Super Blue Racing DOT 4 Brake Fluid - 1 Liter: Automotive or Motal 600 Motul RBF 600 Racing Brake Fluid : Amazon.com : Automotive I flushed the fluid when I got my roadster and the fluid was contaminated... I also perform a bleed every 6 months, you just squirt about 1 ounce of fluid from each caliper just to get fresh fluid in them then top off the reservoir.
wiztecy
Active Member
strider
Active Member
It's just a good idea to do it regularly (every 2 years in my cars and every year on my motorcycle). Also can't see what's going on in the calipers so there could be moisture there. I use a Synthetic DOT 4 fluid - don't use DOT 5.
I've used a Mityvac with my motorcycles when I've had to change lines or calipers and so the system is starting out empty. I used the Mityvac to "fill" the system but still use the "assistant" method to do the final bleed. I've heard the ones that fit onto the reservoir and "push" fluid are better than the ones that "pull" from the caliper but have no first-hand experience.
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