99. That truck was totaled and replaced with a 2020. Next time you install new calipers, check the runout. The powerstop warranty is three years. Ford really screwed me around and said it was my driving habits. . Here are the usual suspects behind brake rotor warping: 1. They replaced the front pads too. 1 out of 5 stars 6 ratings. Buy Power Stop K5368 Rear Z23 Carbon Fiber Brake Pads with Drilled & Slotted Brake Rotors Kit: Brake Kits - Amazon. 002 inch (0. deathb4dismount Crap, didn’t realize my crotch was in that picture. 3 x 9 inches : Country of Origin China : Item model number K690 : Exterior Zinc Plated : Manufacturer Part Number K690 : OEM Part Number K690 : Position. I have never had a problem with them. Is this a case of the brakes running to hot and consequently warping rotors? I had the same problem with my 525i and now on my 330ci. *The primary cause of DTV, or “warped brake rotors,” stems from using an improper break-in procedure or. I want heavy duty pads & rotors since it's obvious OEM-grade stuff is woefully inadequate on these cars. This is where the judder can originate from. The latest were cross drilled and slotted, they lasted the longest but now they are warped again. You almost always have to replace the brake pads to make sure they have a smooth relationship with the new rotors. . Cross-Drilled and Slotted Brake RotorsFrontHighest Quality G3000 Grade Casting BlanksZinc-Plated for Corrosion ResistanceDrilled Holes Keep Rotors up to 180 Degrees CoolerRotor Slots Maintain Clear Contact Between Pads and Rotors Vehicle FitmentFor more detailed fitment information, Click Here!Front: Buick Rainier 2005-2004;. I've always had great luck with PowerStop: I installed them on my '09 LC and '06 GX470 without issue. Posts: 2 druth1028. This physical damage causes harder spots to form in the metal stay, resulting in some slightly bloated rotor surface. Power Stop rotors use only the finest blanks and feature G3000 grade castings from the best foundries. #2 · Jun 25, 2013. They told me the upgraded rotors and pads would reduce the brake fade I experience from driving a 1999 4Runner with a 3 inch Lift and 32s in the mountains. $149. 83 in (275 mm) Front Vented Disc Brake Rotors + Ceramic Pads Kit Compatible with Select Toyota and Lexus Models - ES300 & Camry 97-01, Avalon 98-04, Solara 99-03, 6-PC Set. My front rotors are warped again and was considering aftermarket rotors and pads are these slotted and/or drilled rotors less prone to warpage. 1. Lance. Using these rotors, crafted from a unique carbon-fiber ceramic technology, will make your standard ceramic brake pads much more potent. The Powerstops grab better and just overall brake better than the OEXs. #2 · Jun 25, 2013. I think Ford has some serious Q/A problems with there rotors it sounds like to me. They feel terrible. After researching on this forum, discovered that this is a common problem for Tundras. 2011 Gray Tundra SR5 4. They are squealing sounds when braking, vibrations at the steering wheel and brake pedal, and the vehicle pulling to one side of the road when you apply the brakes. I believe I may buy Hawk slotted rotors, and Hawk green pads. These components are used in street performance and offer. 3 pounds : Product Dimensions 14 x 14 x 8. Installed Power Stops (z36 heavy duty. Product lines. Our 2002 diesel crew cab long bed 4x4 F350. One of key tell-tell signs of run out is a shuttering sensation rather than a pulsing sensation that comes from a warped rotor. The only time you’ll need to replace your brake pads and rotors is when the pads are worn and your rotors are warped, though that doesn’t happen often. 2. 2 pounds : Product Dimensions 14 x 14 x 14 inches : Country of Origin China : Item model number K6023 : Exterior Zinc Plated : Manufacturer Part Number K6023 : OEM. Precision cross-drilled for maximum cooling and maximum performance during extreme conditions. I'm wondering if anyone else is having problems with their front brake rotors. . Now when you get them be sure to check and see. Pads seem great, rotors warped with an 8000 miles I am not heavy on the brakes and do not haul a lot of weight on a regular basis. Power Stop K2009 Front Ceramic Brake Pad and Rotor kit is a great all in one brake replacement kit. Premium stainless-steel hardware, along with ceramic brake lubricant, is included with the Z37 brake pads making it easier to complete your brake job. $202. Also referred to as "warped" rotors, though they don't really warp. The powerstop warranty is three years. The aluminum silver color of the coating looks great with today’s open. Same thing happened on my 2020 only sooner, had them turned down and now they are pulsating again at 38k miles. I got those for the front, but the rears were out-of-stock, so I thought I'd try the Raybestos E3 because they seem to be popular on here and the. #1 · Oct 31, 2018. I've been driving for over 25 years, and have had many vehicles, including 2 XJs, 5. The second is fluid boiling, the effect is a mushy pedal. 5yrs and 15Kmi on a set of made in China Rotors and ceramic pads, both from Napa. 75% of motorcycle accidents are caused by faulty brakes, with warped rotors being a major contributor. In the absence of telltale signs involving one’s sense of smell or touch, this is probably the most obvious sign to tell if a brake rotor is bad. Joined Sep 29, 2009 Messages 3,189 Location Deep in the heart of Jersey. Brake camry toyota rotors am v6 passenger 0l rotor 1997 driver 1999 rear piece side front set2004 toyota camry brake rotors. Power Stop : Model Power Stop K690 Front Z23 Carbon Fiber Brake Pads with Drilled & Slotted Brake Rotors Kit : Item Weight 24. If one hangs up just a bit more than the others, you can bet that one will be more noticeable. Power Stop rotors use only the finest blanks and feature G3000 grade cast iron from the best foundries. The rotors warped in 12,000 miles. 4. Best Easy to Buy Performance Rotors: Napa Reactive One Slotted; 5. Wheels, Tires, and Brakes. Share Arguably more important than the ability to accelerate and steer your vehicle is the capacity to bring your vehicle to a stop. Factory rotors warped at 20k. It's all for looks. BigCahuna. From cRockauto, get the Raybestos Element3 or Bosch quietcast rotors with RaybestosEHT or Akebono ASP pads. The first possibility is that the brake pads are not properly seated in the caliper. #1. Reply Jokka42. They feel. Power Stop LLC warrants its rotors and pads (excluding Track Day and Track Day Spec pads) to be free from defects in materials or workmanship for 90 days from the purchase date or 3,000 miles of use, whichever occurs first. Power Stop LLC warrants its rotors and pads (excluding Track Day and Track Day Spec pads) to be free from defects in materials or workmanship for 90 days from the purchase date or 3,000 miles of use, whichever occurs first. Offer low dust and long pad life. 3 Crew Cab 4x4 302,000+ miles. Proper lugnut torque seems to be the best way to prevent it. We make it simple by matching the pads and rotors for a big brake feel without the big price. Actually warped - about . 1-Click Extreme Z36 Truck and Tow Drilled and Slotted Front Brake Kit without Calipers (K4713-36) by Power Stop®. Excursion - King of SUVs - Time for new brakes: anything wrong with power stop rotors and hawk hp pads? - Time for at minimum new front rotors and 4 pairs of pads. A warped rotor is one where the rubbing surface is moving side to side looking down the length of the vehicle. This causes the rotor surface to be uneven making the brake pedal feel jittery, and the brake system less efficient. A place for 4Runner enthusiasts to gatherHighlights: Effective performance overhaul for your brakes. With JEGS's lowest price guarantee, you are sure to get the best products on the market, and at an unbeatable price. Power Stop LLC warrants its rotors and pads (excluding Track Day and Track Day Spec pads) to be free from defects in materials or workmanship for 90 days from the purchase date or 3,000 miles of use, whichever occurs first. I've done 2 track days on my auto zone rotors running very aggressive Hawk brake pads. 3 x 14. Constant braking: If you're ever driving down a long hill and are. When you have bad rotors, you might feel your car shake or vibrate when you press the brake pedal. Not satisfied with the brakes on our 2013 Pilot, and fully aware that the brake rotors on newer Hondas are prone to warping early because I had this same issue with a 2003 Acura TL. #1. They are brand new so can't comment on longevity yet. Most foundries lower carbon content to increase tensile strength and hardness. Noises while braking. 78. Read more. The rotor surface could then be measured as the rotor is turned by hand. A-Premium 10. Warped rotors are the most common cause of brake vibration in a car. OP. Upgrade King: Power Stop Drilled/Slotted Rotors and Ceramic Brake Pads. I've got about 1. Total price: Add both to Cart. Quantity: 2 Per Pack. Went back again and got a mechanic to test-drive. 10 best brake rotors for toyota camry Rotors slotted drilled powerstop camry vented carid calipers z23 truckid 10 best brake rotors for toyota camry. The average cost to replace a warped rotor is around $300, making it a costly problem for motorcycle owners. Power Stop LLC warrants its rotors and pads (excluding Track Day and Track Day Spec pads) to be free from defects in materials or workmanship for 90 days from the purchase date or 3,000 miles of use, whichever occurs first. Warped or damaged rotors can cause your brake pads to wear unevenly, resulting in the need for them to be replaced sooner than normal. Have to call for replacement rotors. I opted for the powder coated Powerstop Tundra calipers cause red makes me stop faster. They were very easy to install and offer a little more braking. Rotors warped at 44k . 2013. If the warped rotor is on the drive axle of the car, the stopping time of your vehicle. 35. Buy Power Stop K3166 Front and Rear Z23 Carbon Fiber Brake Pads with Drilled & Slotted Brake Rotors Kit: Brake Kits - Amazon. This happens when the brake pads get very hot which causes the pad material to rub off onto the brake rotors. This item: Power Stop K1542 Front Z23 Carbon Fiber Brake Pads with Drilled & Slotted Brake Rotors Kit. 2011 Caravan T&C. Not sure if it is the front or rear or both. All drilled and slotted rotors (except for hub rotor assemblies) are silver zinc. 2. Power Stop 1-Click Performance Pad, Rotor, Drum and Shoe Kits include 2 Power Stop Drilled and Slotted brake rotors, a set of Power Stop Z23 brake pads, a. Save. Power Stop drilled and slotted rotors give you the advantages of both drilled holes for cooling and slots to sweep away gas and dust. Lasted a couple years. Warped brake rotors can cause excessive wear of your brake pads and in severe cases, can even impact. Really aggravating. 06/29/2023. I can't beleive all the reports of brake problems I read about here are caused by the "driver". With that in mind, I went for the Centric High Carbon Plain 125 Series Cryo-Treated Rotor that LethalCamaro installed on his 2SS, along with the power stop ceramic z26 pads. I have gone through 3 sets of rotors and pads in 30K miles. Wear and tear is the simplest reason. Since learning all this, I do the following and have eliminated all brake shimmy in my personal fleet. 3 Resistance to corrosion. 16 votes, 22 comments. Youre much better off with a blank rotor. Plus the rotors look sick. Pioneer single din (tape deck swap) with 3 way active. within months the rear right caliper was leaking. 0 out of 5 stars Warped in less than a year. I have put new rotors and pads on the front three times, and twice I’ve had the rotors resurfaced. Do some research and buy top quality parts, that has helped me out on problem vehicles more than a few times. Most PowerStop brake kits are a direct, bolt-on replacement for original equipment, providing the easy and affordable upgrade for your vehicle. 0 out of 5 stars warped after 2 months. 106 posts · Joined 2017. A few months back I spent $300 on a set of Powerstop cross-drilled rotors and EBC Green Stuff brakes pads. I sold my camper so I rarely tow now. . 16 votes, 22 comments. When they’re warped your brake pads can’t clamp your rotor as easily. Whenever brake pads are replaced, the rotors should also be replaced or resurfaced to allow the new pads to be properly bedded. I've been driving around with warped rotors for the last 1/2 year (slightly warped, only pulsating at high speed, with steering wheel wobble). 1 star. Backstory: a couple years ago I bought a 2005 legacy gt 5mt, and I noticed the rotors were warped. Power Stop : Brand Power Stop : Model Power Stop K6023 Front and Rear Z23 Carbon Fiber Brake Pads with Drilled & Slotted Brake Rotors Kit : Item Weight 96. 3 x 14. 5 pounds : Product Dimensions 14 x 14 x 10 inches : Item model number K2813 : Is Discontinued By Manufacturer Yes : Exterior Zinc Plated : Manufacturer Part Number. 010 runout on one side. "UN-blocked by Sweden!" 2019 S60 T6 R-Design w/sport chassis. The outermost pads both had the "lip" which now i realize is from inadequate surface for the pads to act on. How to Prevent Warped Rotors. POWER STOP Brake & Wheel Hub : Rotor & Brake Pad Kit Auto Parts ALL THE PARTS YOUR CAR WILL EVER NEED Show Prices In US Dollars ($) Australian Dollars (AU$) Brazilian Real (R$) British Pounds (£) Canadian Dollars (CAD$) Chilean Pesos (CL$) Euros (€) Japanese Yen (¥) Mexican Pesos (Mex$) New Zealand Dollars (NZ$) Norwegian. Front Brakes (pads and turning rotors): Brake Pads: $77. pacman359. For example, if one side of the caliper is sticking, you’ll see more wear on one side of the rotor. Best Premium Rotors: EBC Brakes Dimpled and Slotted; 4. 2 new rotors are on order to be installed tomorrow, but Service Mgr. POWER STOP KOE1052 (2x JBR711 + 17562 = (2 * 19. Centric solid discs that are warping fast,Power Stop rotors are cast using the finest G3000 metallurgy with strict OE tolerances - making them a perfect, bolt-on upgrade without the need to make any modifications. Jan 16, 2013. I've got about 1. Power Stop 1-Click Brake Kits include a complete set of cross-drilled and slotted rotors and high performance Evolution Sport Carbon Fiber/Ceramic pads. Nissan Frontier 2008, Performance Floating Front Brake Calipers by Power Stop®. I now notice the shaking whenever I brake. Just get the plain ones and make sure to clean them and bed them in properly. rock between dust shield and rotor. After installing new disc rotors and/or brake pads, perform eight to 10 slowdowns applying moderate pressure from about 30 to 40 mph (50 to 60 kph) without coming to a stop. Power Stop rotors have a carbon content that is 3% more than competitive brands, while maintaining a 210 Brinell hardness and 250 MPa tensile strength. Purchased the full set of calipers and rotors from them. New rotors $186. 1. S&B. Then do 5 moderate stops from 35 mph to 5 mph in rapid succession without letting the brakes cool. Read review. If your rotors need replacing, though, expect to spend upwards of $100 per part, as well as the costs of labor at your nearest repair shop. , Pack of 1. Increased braking performance. Helpful. . 3 Steering Wheel Vibration. If your rotors are severely damaged you may need to replace them entirely. Fit perfectly on my 04 Avalanche Z71 and look great to boot. 1. So thinking the calipers were still sticking I bought rebuilt calipers and had the rotors turned. Power Stop : Brand Power Stop : Model Power Stop K5334 Front Z23 Carbon Fiber Brake Pads with Drilled & Slotted Brake Rotors Kit : Item Weight 48. Stock brakes on a non-t8 xc90 are pretty much junk. Glazed rotor due to lack of bedding procedure done. 5 Easy Installation. Bosch QuietCast™ Premium Front Brake Rotor goes for $328. I looked into the Zimmermann rotors as well and have heard good reviews but looks like they only come. +. -Power Stop Evolution Brake Pads CONS: rotors rust on the outer ring, slotted and drilled holes. We bought the vehicle new and had to have the rotors resurfaced at 22K. Installed Power Stops (z36 heavy duty. Helpful. 7L Hemi. Warped rotors will usually cause the steering wheel to shake. Feeling a vibration in the steering wheel while driving can indicate warped power stop rotors; Warped rotors can be both annoying and dangerous; Understanding the causes of rotor warping and how to prevent it is important; This blog will cover the science behind rotor warping and preventative measures See full list on askcarmechanic. Checking all rotor's width at 8 spots round the disc with a micrometer. Next Step. I had a 1984 Volkswagen Jetta that ran the same rotors for over 150,000 mi. Its good for now. Mar 20, 2008. Maximal surface area = maximal stopping power. 1. They have not warped. Verified Purchase. can cause a brake shudder and this could be especially true if the part in question is slightly worn instead of flat worn out. The original GM rotors warped, were cosmetically rusted beyond recognition, and squeeled like an 18 wheeler truck! This is typical for The new Power. Both the rotors and drums where packaged well and machined extremely well. Warped again within a year worse than the factory rotors. $89. 4-piston calipers, and larger pads), a better braking pad/rotor compound, and so much more. Large edge on the rotor’s surface. Even a quarter mile riding the brakes could overheat the rotors enough to contribute to warping. Original 2015 4Runner front rotors were warped and steering wheel would shake on brake so swapped them out to these and they’re beautiful! Stopping power also increased. In reality, however, the rotor isn’t actually warped but has excessive thickness variation (parallelism) or rotational side-to-side movement (runout). *The primary cause of DTV, or “warped brake rotors,” stems from using an improper break-in procedure or executing. 2000 Mustang GT-Former giggle gas addict. Like a lot of people, my front rotors have been pulsating for a while now. 5 pounds : Product Dimensions 14 x 14 x 10 inches : Item model number K2813 : Is Discontinued By Manufacturer Yes : Exterior Zinc Plated : Manufacturer Part Number. $22139. Warped rotors occur when the brake rotors in your car develop deformities due to excessive heat buildup, aggressive driving habits, incorrect installation of brake components, aging brake systems, and poor-quality brake components. Read honest and unbiased product reviews from our users. ) I currently have 2001 type on it on all 4 corners. 1-Click Z23 Evolution Sport Drilled and Slotted Axle Pack Brake Kit by Power Stop®. In mid-October 2019 I changed my front stock Brembo rotors and pads which were warped (pulsing in the pedal and shaking in steering wheel under high speed braking) at 45k miles. Available in Performance. This causes the rotor surface to be uneven making the brake pedal feel jittery, and the brake system less efficient. The kit came with everything needed to properly replace and install your front brake pads and rotors. 2014 Tacoma DC 4x4 TRD Off Road. not blazing just normal driving and brake use. 2001 F350 Crewcab DRW. When Special jobs are done,, all rotors are dropped off to be machined true first. At this point the only culprit I can think of could be the brake caliper itself but it seems ok. #2. Absolutely no degradation of stopping power. The noise was not due to any problems in the braking system; I believe it was just the nature of the slotted rotors. 10 best brake rotors for honda accord. Got another set from them for free, same deal. 1994-2004 Mustang warped rotors are easily identifiable by vibrations during braking. Stress Cracks: Stress cracks are small “flake” style cracks all over the surface of the rotors. Your Sportage may have drum brakes on the rear though. Technohead said: Its highly unlikely, verging on impossible, that you would permanently warp a rotor because lug nuts were over torqued or not torqued in the proper sequence. Factory rotors warped at 20k. . I bought the powerstop k137 rotor and pad kit in Sep 2019. I had a 1984 Volkswagen Jetta that ran the same rotors for over 150,000 mi. The OEM rotors also warped. Also I'm told by PowerStop that the holes help keep the rotors dry by giving water a way to escape when driving in very. Not satisfied with the brakes on our 2013 Pilot, and fully aware that the brake rotors on newer Hondas are prone to warping early because I had this same issue with a 2003 Acura TL. Purchased and installed them after talking to an AutoAnything representative. 24k miles now, no issues. #4. 3. Here’s a look at the signs that your brake rotors are on their way out and your options for brake rotor resurfacing or replacement. Today - May 2022 - a trusted mechanic let me know that my pads and rotors need changing. Rotors are normally flat and smooth, and as the brake pads clamp down on them, your wheels stop. Most foundries lower carbon content to increase tensile strength and hardness. Reviewed in the United States on October 1, 2015. 7 pounds : Product Dimensions 14. I had the local shop I'm friends with do the labor, not even two weeks went by and the rotors where already warped. YourMechanic’s technicians bring the dealership to you by performing this job at your home or office 7. This occurs because your brake. Best Complete Rotor Kit: Detroit Axle 4 Disc Replacement Kit; 6. Delivery & Support Select to learn more . Even if the surface is smooth, the vehicle will still take longer to stop. Save Share. Ive noticed some vibration when I go to brake which I am assuming is a warped rotor or stuck guide pins. Makes life so much simpler and gets the job done diagnosing the problem too. #12 · Jun 22, 2021. *The primary cause of DTV, or “warped brake rotors,” stems from using an improper break-in procedure or executing. Rotors do not warp - that's a myth that even many of the most experienced mechanics continue to push since they really do not understand what is taking place. 26. 20. Best Value: ACDelco Silver Brake Rotor. Product lines. Upstate NY. Engine. If your rotors get warped you can’t have them turned at the machine shop. 5yrs and 15Kmi on a set of made in China Rotors and ceramic pads, both from Napa. You almost always have to replace the brake pads to make sure they have a smooth relationship with the new rotors. Power Stop Rear Z23 Carbon Fiber Brake Pads with Drilled & Slotted Brake Rotors Kit. That shaking or shuddering during braking is caused by brake pad deposits. Power Stop® - Evolution Tru Cast Drilled and Slotted Rotors Power Stop® - Brake Pads Installation Instructions Power Stop® - Warranty Power Stop® - Products Features Power Stop® - Guide PowerStop Authorized Dealer. However, they aren’t immune to damage or failure due to various factors. After replacing them, I did monitor the rotor temps using a small thermometer just stuck through the. Fast-forward to April 2020 and 10k. Squealing Sounds When Braking The uneven surface of warped rotors prevents the brake pads from meeting smoothly causing a squeaking or squealing noise. Power Stop KOE5334 Autospecialty Front Replacement Brake Kit-OE Brake Rotors & Ceramic Brake Pads : Item Weight 47. Glazed rotor due to lack of bedding procedure done. I have a 2010 Pilot that keeps warping the front rotors, but more specifically the right front. cowfodder. Seems to occur when the brakes are heated up. 79. 0. Messages. 3 x 14. Shimming the rotors will change the run-outs in the rotor. FWIW. It is so nice being able. Machining both rotors, labor $199. Brake dust can cause rotor warping when it gets into the rotors. Then this issue wouldn't have reared its ugly face again. Performance Over Stock. ADD TO CART. I understand that most any rotor can be warped doing stupid things. *The primary cause of DTV, or “warped brake rotors,” stems from using an improper break-in procedure or executing. Power Stop : Brand Power Stop : Model Power Stop K114-26 Front and Rear Z26 Carbon Fiber Brake Pads with Drilled & Slotted Brake Rotors Kit : Item Weight 48. Both. Now I'm running the Powerstop Z36 pads/rotors. Report. I feel the power stop rotors should have a little more surface area for the outer pads to act on. 15,445. Were the lug nuts tightened in three rounds in proper sequence to the correct final torque?. Kit Includes: Evolution Drilled and Slotted Performance Rotors, Z23 Evolution Sport Carbon Fiber Infused Ceramic Brake Pads,. Rebuilt it myself. Autospecialty OE Front Brake Rotor (AR8745) by Power Stop®. The frequency of rotor replacement depends on factors like rotor quality and driving conditions. Paired with some good quailty pads, and its a great budget upgrade. Remove any uneven deposits. Dusty Rusty 2012 Subaru Outback 2. Junior Member . Done some comparison shopping. Power Stop Evolution Performance Drilled and Slotted 1-Piece Front Brake Rotors go for $1,240. Power Stop : Brand Power Stop : Model Power Stop K6023 Front and Rear Z23 Carbon Fiber Brake Pads with Drilled & Slotted Brake Rotors Kit : Item Weight 96. so front and. 70%: 70% of motorcycle owners have had to replace their warped rotor at least once in their lifetime. 0 PSD Arnott airbag kit. 8 Handle Heavier Loads Better. $32908. 001 inches. Second: The heating and cooling that people refer to when discussing “warped brake rotors” would cause cracking, not warping. In the past people here have said that rotors don't "warp". Choose quality rotors: You should also make sure you have. Hard Braking. $246. Don't worry, though, as the fix is relatively. . This is to: Smooth out the rotor surface. Had rotor comeback issues with PS. This causes the brake rotor surface to become uneven and decrease the overall efficiency of the brakes. Every time you press the brake pedal, the brake pads clamp down on the rotor to create friction. Use them for a long time and all of that heat and friction is going to end up taking its toll on the metal. When you feel pulsing in the brake pedal, that is most often caused by an uneven transfer of resins from the pads to the rotors. Love the StopTech products. It happens with hard braking where the pads heat up quickly then sit in a spot on the rotors after coming to a stop where some of the material melts onto the rotors creating an uneven surface. Power Stop LLC warrants its rotors and pads (excluding Track Day and Track Day Spec pads) to be free from defects in materials or workmanship for 90 days from the purchase date or 3,000 miles of use, whichever occurs first. 78. Power Stop rotors are cast using the finest G3000 metallurgy with strict OE tolerances - making them a perfect, bolt-on upgrade without the need to make any modifications. Adherent Friction: For adherent friction, a thin layer of material is. Jul 11, 2021. 1. i think i still have the rotors. Which removes mass, weakens the rotor, causes all sorts of stress risers and turns the rotor surface into a cheese grater for the pads.