48 votes
Accepted

Dealership says European cars need rotors replaced with every pad change because they use softer metals in rotors

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, ...
GdD's user avatar
  • 16.4k
31 votes

Do I need to replace my rotors?

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 ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
18 votes

Mechanic sent me this image and said my brake rotors should be replaced. Does this seem right?

The shiny rings on the rotors are the only parts that are doing any useful work braking the vehicle . The dull rings are rusty and are not serving any use. The rust rings will have worn the matching ...
HandyHowie's user avatar
  • 25.2k
16 votes

What can cause perfect holes in brake rotors?

These are stomata (gas bubbles) in the cast iron or cast steel of your brake rotors. Stomata are usually perfectly round, but may be teardrop-shaped. They are sometimes not visible in the original ...
MTA's user avatar
  • 5,900
12 votes
Accepted

Can I fit thinner disc brakes to my car?

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 ...
Solar Mike's user avatar
  • 34.7k
11 votes
Accepted

Replace driver side first, then passenger side brakes?

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 "...
JPhi1618's user avatar
  • 13.3k
11 votes
Accepted

Is grinding the "ear" of a disc brake pad ok to make it fit?

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 ...
Fred Wilson's user avatar
  • 11.6k
10 votes

What causes brakes to pulsate right after rotor and pad replacement?

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 ...
kmarsh's user avatar
  • 2,159
10 votes

Rotor Replaced and MY Car is only 3 years old

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. ...
JPhi1618's user avatar
  • 13.3k
10 votes
Accepted

What grade of bolts should I use for motorcycle brake hardware?

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 ...
juhist's user avatar
  • 14.6k
10 votes

What do you do when brand new pads are rubbing on new rotor? It smokes and smells so bad and it seems like it is going to catch on fire

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 ...
GdD's user avatar
  • 16.4k
10 votes

If my brakes are making a metal on metal noise, it is pretty much guaranteed I should replace my rotors along with my brake pads?

Squeaky brakes are often the wear sensor, when the pads get low on material they're designed to squeal so you know they need attention. So, you'll almost certainly need pads. As to whether you need to ...
GdD's user avatar
  • 16.4k
9 votes

Is a rubbing disc brake dust cover the first symptom of a bad wheel bearing?

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 ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
9 votes

Dealership says European cars need rotors replaced with every pad change because they use softer metals in rotors

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 ...
Solar Mike's user avatar
  • 34.7k
9 votes

Mechanic sent me this image and said my brake rotors should be replaced. Does this seem right?

Those look to be worn and scored. As a minimum they need to be resurfaced, which many shops are not equipped to do. They may also be at or below the service limit so resurfacing is not an option. If ...
jwh20's user avatar
  • 12.1k
8 votes
Accepted

How much disc brake drag is acceptable?

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,...
sweber's user avatar
  • 7,057
8 votes

Do I need to replace my rotors?

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 ...
GdD's user avatar
  • 16.4k
8 votes

What can cause perfect holes in brake rotors?

It looks like the car sat for awhile in the past and the (worn) pads developed rust. The rusting rivets on the pads probably ate those holes into the rotor. Look at all the other rotor surfaces. Brake ...
John Canon's user avatar
7 votes

Rotor Replaced and MY Car is only 3 years old

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 ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
7 votes
Accepted

What are the visual signs that brake rotors must be replaced?

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"...
JPhi1618's user avatar
  • 13.3k
7 votes
Accepted

What type of Brake Lube to use

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 ...
Fred Wilson's user avatar
  • 11.6k
6 votes

How much disc brake drag is acceptable?

To my mind, a wheel should spin freely when spun on the jack. A little noise is acceptable but if the wheel is clearly being slowed down excessively or is particularly hot after use, something is not ...
Steve Matthews's user avatar
6 votes
Accepted

If I am replacing a brake caliper should I also put in a new rotor, even if the existing one is in spec?

No, if the rotor is in good condition – no grooving and thicker than the wear limit – there is no need to replace it. If it is marginal, scored or almost down to the wear limit, then it would be a ...
dlu's user avatar
  • 14.5k
6 votes

New pads braking cause medium steering wheel vibration, shims were not replaced, rotors look good

Vibration through the steering wheel is generally caused by a defect in a rotating part or an imbalance in a rotating part. Note: neither pads nor shims rotate. If the problem is the same after you ...
Tim Nevins's user avatar
  • 1,046
6 votes

What do you do when brand new pads are rubbing on new rotor? It smokes and smells so bad and it seems like it is going to catch on fire

In a properly functioning brake system the pistons in calipers must be free to move (in both directions). When brakes are applied, the fluid is under very high pressure thus generally the pistons will ...
D. SM's user avatar
  • 683
6 votes

Dealership says European cars need rotors replaced with every pad change because they use softer metals in rotors

Bull; find a dealer that can make up better stories. Rotors are grey cast iron; now I don't want to lie like your dealer, there may be some nodular or malleable cast iron rotors. It would require ...
blacksmith37's user avatar
  • 3,698
6 votes
Accepted

How does the brake fluid return to reservoir in Disc Brakes after brake pedal is released?

In the caliper, the seal is designed so when you press the brake pedal and fluid enters, the seal twists sideways. When you release the brake pedal, the force of the seal pushes the piston and thus ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
6 votes

Do extremely rusty disc brake rotors/pads need to be replaced?

Repair shop liability issues dictates SAFETY FIRST. Brake repairs are safety issues so there's no cheap economical repair. However, you can, if possible, seek out another repair shop and ask for an ...
F Dryer's user avatar
  • 976
5 votes
Accepted

Standard vs Carbon Ceramic Brake Discs - What do you pay for?

The huge size is not limited to carbon ceramic, that's just an attribute of most high performance cars' rotors. Carbon ceramic brakes are more expensive because the exotic compound does a much better ...
Tyler's user avatar
  • 417
5 votes

Wheel stuck to Rotor

The easiest way to take care of this which I've found is to: Jack up and secure the vehicle (or wheel) Take all lug nuts off Sit on your butt in front of the offending wheel With your feet, pound ...
Pᴀᴜʟsᴛᴇʀ2's user avatar

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