wiztecy
Active Member
FYI the the brake quiet spray was what the original pads had on them, didn't you have an issue pulling the oem pads off? They should have felt "glued" on... that is what keeps them from rattling.
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Brake Pads
- Thread starter Roger Reid
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- Performance Roadster
Vger
Active Member
More of the story: I had it done by Tesla Vancouver, so I did not see how tight the OEM pads were. Spray (or something) was supposedly used on the AX6's, but the pads began to rattle after a few weeks. I was then on a long road trip, so was worried about a sound nobody could identify at that point. So I had the Roadster experts at Tesla Fremont Service attempt to diagnose the issue. Interestingly, it quite stumped them for a whole day.
Eventually, they swapped the pads back to OEMs, and the rattle disappeared. Not willing to give up the AX6's, I had them refitted in a hurry at the end of the day. I think they likely used NO goo that second time, so the rattle was much worse. I lived with it on the way home, and then researched TMC, this font of all knowledge, and realized what was happening all along. I now have the buffer pads from Elise-Shop, but have still not had a chance to try them and/or CRC yet.
BTW, even Tesla Fremont were completely unaware that many of us had switched to high-performance pads to great effect. This is probably why they could not identify the rattle promptly.
Eventually, they swapped the pads back to OEMs, and the rattle disappeared. Not willing to give up the AX6's, I had them refitted in a hurry at the end of the day. I think they likely used NO goo that second time, so the rattle was much worse. I lived with it on the way home, and then researched TMC, this font of all knowledge, and realized what was happening all along. I now have the buffer pads from Elise-Shop, but have still not had a chance to try them and/or CRC yet.
BTW, even Tesla Fremont were completely unaware that many of us had switched to high-performance pads to great effect. This is probably why they could not identify the rattle promptly.
Just joined the AX6 club & impressed / happy with the initial bite. Somewhat surprised that the original rear pads were nearly wort out (32,000 miles) - even wear across all pads so unlikely to be due to sticking pistons etc. Perhaps caused by me doing an emergency stop each morning to make sure the pads are warm / work when I need them.
I really missed a trick - at work we make PC based oscilloscopes (PicoScope) and also accelerometers. It would have been easy to trigger a scope from the brake switch and plot the deceleration & stopping distance with the OE pads and AX6 (both cold and warm). Not going to the hassle of putting the old pads back to do it though!
I really missed a trick - at work we make PC based oscilloscopes (PicoScope) and also accelerometers. It would have been easy to trigger a scope from the brake switch and plot the deceleration & stopping distance with the OE pads and AX6 (both cold and warm). Not going to the hassle of putting the old pads back to do it though!
wiztecy
Active Member
Doesn't the VMS have that capability? It does have an accelerator and can register G's.... It does register acceleration so I'm guessing deceleration.... I turned that screen off but possibly if someone's interested they can check it out.
Does anyone have any input on Bobcat/1521 vs. AX6 in terms of noise?
My car currently has squeaky wheels, and when I attempt to fix that problem, I figure I might as well replace the pads at the same time. I don't *plan* to track the car, but anything could happen, and I do tend to overdrive the car on the street anyway. However, I'm very regen-aware, and barely ever use the friction brakes in normal day-to-day driving. The car will be kept outside, and in Southern California, where the weather will rarely make the brakes very cold.
So, mainly, I'd like cold stopping power and as little noise as possible. Would the 1521s offer enough of an improvement over the AX6s to make it worthwhile, or is the extra stopping power on the AX6 just that good?
My car currently has squeaky wheels, and when I attempt to fix that problem, I figure I might as well replace the pads at the same time. I don't *plan* to track the car, but anything could happen, and I do tend to overdrive the car on the street anyway. However, I'm very regen-aware, and barely ever use the friction brakes in normal day-to-day driving. The car will be kept outside, and in Southern California, where the weather will rarely make the brakes very cold.
So, mainly, I'd like cold stopping power and as little noise as possible. Would the 1521s offer enough of an improvement over the AX6s to make it worthwhile, or is the extra stopping power on the AX6 just that good?
wiztecy
Active Member
My AX6's stop very good, in theory they'll bite harder than the 1521s. However Strider is very happy with his 1521s. CarboTech says that the 1521s are quieter and produce less dust than the AX6's. The only time I heard any noise from my AX6's was when I was breaking them in and that was it. They're quiet as quiet can be. As for the dust, they produce way less dust than the stocks... I don't wash my car every week, go for 3 weeks to a month and the dust doesn't drive me crazy. So if you're worried about dust I'd go with the 1521s. Either way is a huge improvement over stock. I wanted the best bite and didn't care about dust... when you need to stop you have to do it in an instant and every foot counts!
Not tried 1512s but for me there is no difference in noise I can tell between the AX6 and stock pads.
Like Wiztecy I dont wash the car often & also have black wheels but not noticed any dust.
No regrets from the AX6 choice so far - I was after increased stopping power from cold and they have delivered on that.
Like Wiztecy I dont wash the car often & also have black wheels but not noticed any dust.
No regrets from the AX6 choice so far - I was after increased stopping power from cold and they have delivered on that.
For me the AX6 are much quieter than the stock pads, and have way more stopping power regardless of whether they are cold or hot.
Another very nice feature is that they clean the rust off the rotors in normal driving, without you having to do hard stops once a week. That is a big problem with the stock pads.
Another very nice feature is that they clean the rust off the rotors in normal driving, without you having to do hard stops once a week. That is a big problem with the stock pads.
How is this possible without the brakes dragging/reducing efficiency/making noise? Or do you mean that just the few times you do use the brakes, they clean the rotors better than the stock pads?
Yes, you use the brakes occasionally just in normal driving, and they scrub the rotors clean. With the stock pads the rotors get progressively worse until they work like crap - pretty quickly in fact - and you have to go out and do multiple hard stops to scrub them off.
strider
Active Member
Unfortunately the Roadster's brakes last so long none of us have used both to know for sure. As wiztecy said I am thrilled w/ my 1521's. No noise and no dust yet they haul the car down fast whenever I need it to. My car is a daily driver and I also rarely use the brakes except when traffic does something stupid and I need the brakes RIGHT NOW. The stock brakes gave me a few moments when I would be standing on the pedal and the car was barely slowing down.
So maybe someday we'll get some cars side by side and try to do some comparisons but there are a lot of variable that go into braking distance like suspension setup and tires. But at the end of the day I don't think you can go wrong w/ either one.
The AX6 are intended for autocross, which means they have to work when the brakes are cold. It's really not an issue - they work just great on the street. They're way better than the stock pads even when stone cold.
wiztecy
Active Member
FYI: I'm working with Rob from Dietsch Werks in fitting a 5 lug slotted rotor from a Lotus Europa that we believe will fit the Tesla Roadster / 5 lug design. This will be awesome! If not he's able to convert/setup the 4 lug rotor and even said we could use the 2 piece rotor with the aluminum hat from Lotus. So just dumping some brainstorming from him here. This also means if we want to use the bigger brake calipers from the Elise we can! Rob noted that the issue with braking isn't so much with bigger brake calipers, and he said that the big calipers Tesla had in mind for the upgrade were overkill ( I actually agree and that was my impression ), that just improving with whats there will work.
Some recomendations:
1) Change your stock brake pads to something that actually work, for us we have real live drivers who stand behind switching to CarboTechs and their braking power/improvement.
2) Change your brake fluid ever year. This will help prevent brake fading.
3) Change out the heat conductive aluminum caliper pistons for the high performance stainless steel ones that Rob has and suggested. I have pics below of them.... The aluminum is hurting and heating the brake fluid, it contributes to brake fade. You can see the cups cut-out in the Stainless ones in the pic, that allows the hot air built up in the piston cup to escape. Makes sense.... should be like that from stock as well as stainless!
Feel free to PM me/email me (best since PM fills up fast) if you're interested in any of this. Email link is in my profile link.
Also if you want your Carbo-Techs installed on your Roadster he's the person to call!
Dietsch Motorsports - Lotus Repair and Upgrade Specialist in San Jose CA BMW Mini Porsche
Some recomendations:
1) Change your stock brake pads to something that actually work, for us we have real live drivers who stand behind switching to CarboTechs and their braking power/improvement.
2) Change your brake fluid ever year. This will help prevent brake fading.
3) Change out the heat conductive aluminum caliper pistons for the high performance stainless steel ones that Rob has and suggested. I have pics below of them.... The aluminum is hurting and heating the brake fluid, it contributes to brake fade. You can see the cups cut-out in the Stainless ones in the pic, that allows the hot air built up in the piston cup to escape. Makes sense.... should be like that from stock as well as stainless!
Feel free to PM me/email me (best since PM fills up fast) if you're interested in any of this. Email link is in my profile link.
Also if you want your Carbo-Techs installed on your Roadster he's the person to call!
Dietsch Motorsports - Lotus Repair and Upgrade Specialist in San Jose CA BMW Mini Porsche
wiztecy
Active Member
I also want to add some information that Rob shared about turning your rotors... I told him I had done a cold turn of my Rotors. Rob, just like Tesla recommended replacing the rotor. Here's the reason why... proved on my Roadster. When you cut your rotor... in order to have the rotor disc perfectly cut and on a clean flat level plane it has to match the hat of the rotor (where the lug holes are). He said this is very hard to do and not many people get it right when they turn rotors. We spun/rotated rotor with the wheel off and low and behold we found he was right! The issue where the rotor disk is not level with the hat is called run-out. I noticed when my rotor spun it would catch on each revolution and stick / bind with the pad. This is due to the off-level cut between the brake surface and the hat. Hence why Tesla said to replace the rotors on each brake change. Is it a big deal? Probably not. However I do feel my brakes pulsating a little when I push them hard... now I know where that was coming from.. they were not warped just cut imprecisely. Also since they're dragging on each revolution the Roadster is not being as efficient as it could be and also the pads/caliper/piston/fluid are building up unnecessary heat that help promote brake fade.
Must admit I am happy with the AX6 and the rest as stock, but if anyone is brave enough to try this carbon disk brake set up let us know how it works!
Carbon Front Brake kit (Elise, Exige, 2-Eleven) [FREFRCDP] - 2,625.00 : Elise Shop, Performance parts for your Lotus Elise
Carbon Front Brake kit (Elise, Exige, 2-Eleven) [FREFRCDP] - 2,625.00 : Elise Shop, Performance parts for your Lotus Elise
I didn't turn the rotors nor replace them. Sure you might not have perfect contact at first, but bedding the pads conformed them to the rotors and everything works just fine.
Hmm... I hate to question the wisdom of somebody with Rob's experience but... I'm not convinced this makes sense unless you track your Roadster or are otherwise heating the brakes excessively. For normal street driving the Roadster has a problem with not heating the brake fluid enough because the brakes are rarely used heavily due to regen. Brake fluid is designed to absorb moisture. Normally this moisture evaporates off when the fluid is heated from braking but we almost never heat it up enough to do that. The result is that the Roadster absorbs moisture at a faster rate than it can evaporate, which is why it often turns into a thick sludge faster than most other cars without regen. I change my brake fluid every year for this reason. Tesla recommends every year for the Roadster.
wiztecy
Active Member
Hi Henry, Rob did indicate these points from a "track" perspective and also said that we'd more likely have the glazing effect on the street where you stomp on the pedal and nothing happens... such as the experience we had with the stock pads and most likely wouldn't see the fade unless we were constantly on the the brakes hard. At the track if there's moisture in the fluid, this will cause the brake fluid to boil and lead to fading. My fluid hasn't been changed and its something I really need to do. He said that if you see discoloration its a good indication the fluid is contaminated but its always better to have it replaced before that happens and the system picks up corrosion and such.
Also I'm trying to retain as much information that Rob was passing on to me, so discussion and clarification helps iron things out
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wiztecy
Active Member
I had a rattle coming from the right front brake pad, not CarboTech specific but just brake changes and improved learning process... as the Amazon reviews indicated the Spray Can of the CRC brake quiet isn't all that great, it failed to keep a rigid sticky hold of one of the brake pads. The spray is just too think when applied. I cleaned everything again nicely with brake-clean and applied the CRC brake quiet, that you push out of a clear tube, this stuff is way better and thicker. I did both fronts. I left the rears alone (just sprayed water across the system to clean the grit and dust) No rattle back there and I grabbed each of the pads which proved to be still firm and planted. No need to touch it. I lightly greased the two pins that hold the front pads into the calipers as well as the flat part of the caliper where the brake pads slide against, prevents pads from snagging up.
I inspected the CarboTech pads and cold cut rotors... all is looking good and wearing the way they should, I'm happy. No signs of cracks or any issues with the pad breaking down. Always good inspecting your brakes every now and then... They're pretty important. I had some pebbles laying around on the caliper, gave everything a good cleaning including the rotors/holes/fins on the front / back brakes and the system is looking good.
Also did a full brake bleed of the system. I bought the push style pressurized brake bleeder kit as recommended in this thread, worked well:
Motive Products Power Bleeder - European- Black Label : Amazon.com : Automotive
This one has the aluminum screw cap, so it may be more expensive than others online. You can make one from a weed spray bottle but I didn't want to go through the hassle. Just make sure to put teflon tape on the brass connection between the pump and the cap, they didn't for some reason... had fluid spill out and didn't know it on the fan cover... discolored it. I put some plastic spray and olive oil on to bring the black back which worked. Beware, brake fluid will eat the plastic and make some chemical reaction. I recommend putting down a large towel to cover the plastics just in case.
I recommend pulling off the brake reservoir... my brake fluid was very old, started to turn an amber color (from the clear translucent color). Knew I had to change it ASAP. I started bleeding the system with the old fluid in the reservoir, well that's a pure waste. It mixes and you can't get all the old fluid out. So I ended up cutting the zip tie and removing the whole reservoir. You can put any long ziptie in there, smaller width is fine. Just make sure its long enough or double them up. The reservoir pulls up after the zip is cut, two bolt/studs that keep it in place (see pic). Just pull straigt up, nothing is going to break. I also disconnected the two tubes connected to the reservoir off from the vehicle side (as seen in pics). Made dumping the fluid out easier and the only way to get the old stuff out.. Make sure to put paper towels down to catch the dripping brake fluid when you pull those tubes off.
I went through 2 liters of brake fluid. You should be able to do one liter if you do it right. Bled the system since I still had a spongy pedal at 1st. I revisited it again and found air in the left rear side of the car. Now the fluid is clear, brakes are tight.
Remember to bleed the caliper furthest away and work in.: 1) Passenger Rear, 2) Drivers Rear, 3) Passenger Front, 4) Driver's Front
I went with DOT 4 brake fluid. You can get it for $8 - $12 a liter. If you want to put the more expensive DOT 4 stuff in, if so, I'd recommend flushing the system with the $8 stuff 1st and then put your $20-$30 stuff in. I think I'll be fine with the standard DOT 4 fluid which meets my street driving spec and above. Note if you put DOT 5 in its incompatible with DOT 4 and below. I don't know how you can entirely clear the system of DOT 4 if you went that route... if anyone knows let us know
Don't need to pull the front wheels to reach the bleed screws, can access them with the wheel on.
The rears, way easier if you remove the wheels, hard to get to. You can get to them from laying on the ground or on a car lift. I didn't pull the wheels with the second bleed but its super uncomfortable.
I inspected the CarboTech pads and cold cut rotors... all is looking good and wearing the way they should, I'm happy. No signs of cracks or any issues with the pad breaking down. Always good inspecting your brakes every now and then... They're pretty important. I had some pebbles laying around on the caliper, gave everything a good cleaning including the rotors/holes/fins on the front / back brakes and the system is looking good.
Also did a full brake bleed of the system. I bought the push style pressurized brake bleeder kit as recommended in this thread, worked well:
Motive Products Power Bleeder - European- Black Label : Amazon.com : Automotive
This one has the aluminum screw cap, so it may be more expensive than others online. You can make one from a weed spray bottle but I didn't want to go through the hassle. Just make sure to put teflon tape on the brass connection between the pump and the cap, they didn't for some reason... had fluid spill out and didn't know it on the fan cover... discolored it. I put some plastic spray and olive oil on to bring the black back which worked. Beware, brake fluid will eat the plastic and make some chemical reaction. I recommend putting down a large towel to cover the plastics just in case.
I recommend pulling off the brake reservoir... my brake fluid was very old, started to turn an amber color (from the clear translucent color). Knew I had to change it ASAP. I started bleeding the system with the old fluid in the reservoir, well that's a pure waste. It mixes and you can't get all the old fluid out. So I ended up cutting the zip tie and removing the whole reservoir. You can put any long ziptie in there, smaller width is fine. Just make sure its long enough or double them up. The reservoir pulls up after the zip is cut, two bolt/studs that keep it in place (see pic). Just pull straigt up, nothing is going to break. I also disconnected the two tubes connected to the reservoir off from the vehicle side (as seen in pics). Made dumping the fluid out easier and the only way to get the old stuff out.. Make sure to put paper towels down to catch the dripping brake fluid when you pull those tubes off.
I went through 2 liters of brake fluid. You should be able to do one liter if you do it right. Bled the system since I still had a spongy pedal at 1st. I revisited it again and found air in the left rear side of the car. Now the fluid is clear, brakes are tight.
Remember to bleed the caliper furthest away and work in.: 1) Passenger Rear, 2) Drivers Rear, 3) Passenger Front, 4) Driver's Front
I went with DOT 4 brake fluid. You can get it for $8 - $12 a liter. If you want to put the more expensive DOT 4 stuff in, if so, I'd recommend flushing the system with the $8 stuff 1st and then put your $20-$30 stuff in. I think I'll be fine with the standard DOT 4 fluid which meets my street driving spec and above. Note if you put DOT 5 in its incompatible with DOT 4 and below. I don't know how you can entirely clear the system of DOT 4 if you went that route... if anyone knows let us know
Don't need to pull the front wheels to reach the bleed screws, can access them with the wheel on.
The rears, way easier if you remove the wheels, hard to get to. You can get to them from laying on the ground or on a car lift. I didn't pull the wheels with the second bleed but its super uncomfortable.
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