48

You are right to be skeptical, the 'softer metals in european rotors' is complete horsedung. A bit of rust is completely normal, the rest of your criteria for replacing rotors is right on the money, if the dealership is trying to pull that line on you then they are either incompetent or trying to run up your bill.


31

While I cannot see the back rotors very well, I can tell you without a doubt, the front rotors are brand new. You can still see the crosshatching on the surface which means it was prepped. It doesn't show any wear at all. The rear brakes (from what I can see) are in good condition as well, though appear to be a bit older and more used. The misconception you ...


16

I would recommend you get slotted, but not drilled rotors. Regular rotors will work fine for typical track use. What is more important is the type of brake pad you purchase to go with your disks. The reason I suggest not getting drilled rotors is, they have a tendency to crack at the holes due to stress risers. They will not last as long as you'd like them ...


13

Contact area Blank rotors have a larger area in contact with the pads than slotted or drilled rotors. Therefore they provide better braking at the same temperature. Cooling To cool the rotor, manufacturers use a vented rotor, not a cross-drilled or slotted rotor. cross-drilling puts holes perpendicular to the flow of air - they have no cooling effect whilst ...


12

You have ordered the incorrect discs, or the supplier has made an error. You will need the correct vented, thicker, disc as the caliper has a « jaw » sufficiently large for the combined thickness of pads and vented disc. If you do try to use the solid disc then the pistons could easily pop out of the caliper and you have zero brakes... Contact the ...


11

I'm going to assume you have a very good reason for not taking the other car out of the garage to give yourself more room... People replace either the front or rear brakes together because they are "on the same axle" and replacing one side doesn't make sense because both sides should wear at the same rate. Replacing one side could make the car pull to one ...


11

This is acceptable practice. Low quality brake pad backing plate edges can be very rough and the dimensions are often off spec. Higher quality pads usually have a better formed edge that fits correctly. As long as there are not rust flakes causing "rust jacking" under the pad end shims and the end shims are in good shape it is OK to file off the high spots ...


10

I've done countless brake jobs at the shop I worked at; without hearing/seeing the car here are some things that can cause noise/pulsating: Non-burnished brakes - like others have stated after putting fresh pads and rotors on a car you need to 'break them in.' I worked in a shop for a while and we didn't always do everything by the book, but when putting ...


10

The only way to know if a rotor needs to be replaced is measuring it with a micrometer and comparing that to the manufacturers specifications, so, no, we can't tell you if it needed to be replaced. However, since this was your first brake job I seriously doubt they needed to be replaced. Common practices is to "turn" rotors when doing a brake job. The ...


10

It does sound like the caliper is not releasing, which means it is bad, or at least needs some repair. You might have corrosion on the slides, or the caliper pistons. The caliper needs to be replaced or repaired, and you will likely need to replace the pad as well. High heat in the brake caliper can cause the brake fluid to degrade, or develop air bubbles. ...


9

The Myth (Or, how to blame customers for bad brake jobs, since the problems usually take a while to show up) What is passed off as a "warped rotor", and blamed on the user running through a puddle after heating the brakes, is a myth. The shimmy feeling that comes from brakes is usually due to uneven friction material build-up on the rotor. This transfer ...


9

No, A2 bolt is not safe. You can use the calculator here: http://www.tribology-abc.com/calculators/e3_6b.htm ...for bolts of grade 8.8 and M8 thread. It will say that the maximum tightening torque is 24.11 Nm which is less than 20 ft lbs (which would be 27.11 Nm). Now, the calculator does not have A2 as the grade of bolts, but according to this site: http://...


9

Your understanding of how it's connected together makes sense, however, if you are rubbing a brake dust cover (backing plate) it doesn't mean the bearing is going bad. The first thing I'd be looking at is if there is any damage to the dust cover or if there is something stuck between the dust cover and the rotor. The reason you wouldn't look to the wheel ...


9

No, rotors can go through 2 or 3 sets of pads. But if a stone or piece of grit causes scoring then they need replacing. Sometimes resurfacing is sufficient but often the time needed is more than replacing with new. Also the rotor thickness should be checked - workshop manuals will give the minimum acceptable thickness as well as values for run-out.


8

The direct answer is that you have to replace your rotors when they look like this:


8

It's pretty obvious from reading all these replies, that the mechanic shops want you to always replace your rotors, and pay them to do it. Rust on the edges is normal and will happen with new rotors in less than a year, depending on where you live. If the rotors have never been resurfaced, you don't have any deep grooves, and your brakes aren't shuddering ...


8

More than likely you didn't bed your brakes correctly. If you read this from Centric Parts, you find out exactly what I'm talking about. The specific part I'm talking about is the portion on an even transfer layer: Note the emphasis on the word even, as uneven pad deposits on the rotor face are the number one, and almost exclusive cause of brake judder or ...


8

What is a freely spinning wheel? Of course, you should be able to spin the wheel by hand, but beneath the brake, bearing and transmission can apply lots of drag. My rear wheels do about 1.5 to 2 turns, my front wheels not more than half a turn when I put them in rotation by hand. While it's the same for the front wheel of my mother's car, its rear wheels ...


8

There's nothing wrong with your rotors as far as can be seen from your pictures, it's totally normal to have the edges rusty, it doesn't impair them. What's important is that the disk surfaces are in good condition, that is the part that's going to be in contact with the pad, and yours seems fine. There looks to be a good amount of metal left as well.


7

This is a great question, so let me help. First, I am the owner an auto repair center in New Hampshire and rusted brake rotors are almost an everyday occurrence here. If you live in an area that uses a lot of salt on the roads in the winter, like we do, then this information most likely pertains to you. 99% of the rotors that we have to replace are due to ...


7

You cannot tell from just looking at them (in most cases) ... you have to measure the thickness of the rotor to see if they need replaced. Also, it's hard to tell from the picture how deep the wear is on the rotor. The grooves could be 1mm deep, or 5mm deep ... it's really hard to tell. It really comes down to how thick the rotors would be after machining. ...


7

Overheated rotors can show some tell-tale signs. Once the metal has been overheated, it can weaken or warp which are both bad things. Some signs: Bluing Cracks These "spider cracks", "heat cracks", or "heat checks" are only on the surface of the rotor, but are still bad.


7

Two lubes are needed to properly lubricate caliper type brakes. Silicone is used on the slider pins and anything that touches rubber. A generous amount that completely coats the pin, hole wall and rubber expansion boot is needed. Be sure to coat the boot lips that fit in the grooves that hold them in place, this act as a sealant. This lube will not swell ...


6

Well, the new rotors and pads were the answer. I'm surprised that the EBC OEM replacements gave me so much trouble, but the new EBC Red Stuff (ceramic) pads and slotted rotors have been wonderful. Even with my typical hard braking, no noise, and better performance, too. (Apologies for the delayed answer. I became sidetracked and completely forgot about this ...


6

It very difficult to say if a rotor is warped by visual inspection. The tolerences involved are very small in the .004" range. That is about the thickness of 3 or 4 human hairs. My recent experience (if you are doing your own repairs) is to replace rather than resurface. The thickness of used and resurfaced rotors may exceed the minimum allowed thickness, ...


6

2mm of friction material is not much. I would suggest you change the pads as they have. They may last a bit longer, but at what point are they going to go metal-on-metal and greatly reduce your stopping ability? At any point, the last little bit may flake off and cause this situation. It could run for 5000 miles or it could last 5 miles? Are you willing to ...


6

Paulster2 offers sound advice when he says the pads need to be replaced sooner rather than later. I recently took a picture when I performed a brake pad swap that offers a stark comparison of what you could be missing out on. The new pads for my BMW measured 10mm at the thickest part. The old pads were roughly 2mm, thin enough to cause my brake pad wear ...


6

Unless the rotor shows obvious signs of damage there is no way to tell by a photo. The only way to be sure is to measure the rotor with a micrometer. The most accurate method is with a micrometer specifically designed to measure rotors. The contact areas of the micrometer are pointed, this allows measurement at the base of any grooves. After the smallest ...


6

Paul, I'd like you to open up those brakes again and examine the rotors very carefully. I just finished a conversation with a fella who described symptoms identical to yours. I walked him through a range of troubleshooting steps until finally I was nearly convinced that he had a cracked CV joint boot and he needed to replace an axle shaft when he suddenly ...


6

It is not normal for the front end to go out of alignment when getting the front rotors turned, but it would not be unheard of. Any time you mess with the front end of the vehicle you run the risk of needing an alignment. This is not something you should expect to be done, though. Something which may be happening is you may have a caliper which is dragging,...


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