In a way that seems to make sense but as the force of the inner pad pushing against the rotor increases it's also increasing the force with which the outside pad is being forced against the outside of the rotor. I've changed pads on a lot of cars with floating calipers over the years and have never seen the remaining pad material of the inner pad to be less/thinner than the outside pad. That's just eyeballing and not measuring but if there were any significant difference I'm sure I would have noticed. Floating calipers would be a disaster if the inside and outside forces on the rotor were not reaching equilibrium almost instantly.

Poorly maintained/corroded floating caliper mechanisms could result in a different story.

 

These were original 70k mile rotors, that looked ok from outside.

 

Not a pretty sight. Certainly looks like "stuff" got lodged in places it didn't belong.

 

Drilled rotors are prone to warping easier than standard or even slotted rotors BTW. Wouldn't recommend for a car like the GLK. Regarding pad slapping, I think it depends where you live. Here in SoCal, where the weather is temperamental and little to no rain (or salt), you can easily pad slap as long as the rotor isn't worn too much or grooved. Would only recommend pad slapping once per rotor however. Also, Akebonos are (or were at least) junk for the GLKs. Keep an ear out for rattling.

 

you are close but rotors almost never warp. Pad material build up sure but not warping. it would take turning them red hot to do that. drilled rotors are probe to cracking though. Slotted rotors are designed to "wipe" the pad.

 

Rotors warp all the time. I probably drive 2-3 cars a week that have warped rotors. I think you are mistaken on this one.

 

Is that the right SKU? https://www.fcpeuro.com/products/mer...glk350-eur1406

You bought 4 of them?

 

I think is why many rotor manufacturers offer cryogenically treated brake rotors that have a denser structure to prevent warping. Often mentioned as a cause for warping is taking a car with hot brakes into an automatic car wash.

 

I've been doing my own brakes, and friends, for about 35 years now. Disc and drum brakes. I bought my 2010 glk350 4matic new and I've done the brakes twice now. The 1st time around 60k and the 2nd a year ago ago at 120k.

My thoughts on the glk brakes are that the brake dust from the early models like mine was absolutely terrible. Wash the car and 2 days later the rims would just be covered and it looked terrible. At 60k the brakes still had a good year on them but I was tired of the brake dust. I had the rotors turned at O'Reilly's and put new Wagner ceramic pads all the way around around. The car stopped great and no dust.

The 2nd time around I bought new rotors and ceramic pads, all Advance Auto parts, and I've had no issues with the pads or rotors.

In my 40 years of driving I've had a few cars where the rotors warped, but it's been years since I've had it happen to one of my cars. It seems like car companies and the after market are doing a better job making rotors.

I've bought a lot of rotors through the years and I've never had one that warped later but I've had some that weren't right straight out of the box. My thought is it's the driver and their driving habits, probably one of those idiots who slams on their brakes all the time and shouldn't be driving.

I've never had a car with slotted rotors but it does seem like slotted rotors with ceramic pads would be a good combination.

I work for a HVAC manufacturing company and like us, the car makers have lots of engineers. My glk didn't come with slotted rotors, since the factory engineers didn't see a need for them, so I didn't spend the extra $ when I bought the new ones last year.

My opinion is just that, an opinion and I appreciate the threads like this one where I can see what others have experienced. If someone wants to buy slotted rotors or just put new pads on old rotors, it's not my job to tell them that's right or wrong.

 

Is that the same as "weren't straight right out of the box"?

 

https://trade.mechanic.com.au/news/s...d-brake-rotors

 

Question regarding this response. I have been following several GLK350 sites since the first of the year. I consistently read about "warped rotors" starting at 20,000 miles and a lot at 50,000 miles and felt I had them on the used GLK350 that I bought in February. Your posted information is well written and has some good facts. But I can't help but wonder why the 2018 Ford Explorer that my wife drives all over the SE for dog shows and now has 88,000 miles on the original rotors and pads. Plus the rotors look like there is very little wear. It couldn't be that MB under designed a set of brakes for a 4,000# car vs Fix Or Repair Daily's 4,400# car?

 

I don't know your exact situation but most break issues are due to driving style and installation. Also you have to factor in performance. A high performance brake set up is not going to last as long as an economy set up. Similar to a performance tire. I run $250 dollar a piece tires on my e55 and they dont last half as long as the $90 dollar tires on my 190e.

I bought my glk and immediately replaced the rotors and pads as I do on all cars. I first started with the akebono pads and they did not fit correctly and made clicking noises. Swapped them to pagdin pads and there has been 0 issues. we have taken it back nd forth on 200-600 mile trips and my wife drives it daily about 9 miles to and from work. Everything works 100% as it should. no groves in the rotors or anything.

I will say to while mercedes makes some nice cars and parts they have made some crap too. why in the world would you think a biodegradable wire harness was a good idea. lol

 

yes I bought all 4, no rattling, been perfect so far in the first 1000 miles of having this rotor and pad set up.

 

yes I bought all 4, no rattling, been perfect so far in the first 1000 miles of having this rotor and pad set up.

 

So the box has 2 pads, meaning the quantity of 2 in the shopping cart?

 

Ok, I figured, EUR1406 for front and EUR1341A for rear, one of each.

 

So this author says "BRAKE ROTORS NEVER WARP" then a few short paragraphs later says "Improperly torqued lugs can cause brake rotor warpage." Ever heard some one say "You can't always trust the Internet"? Well, this is one of those times. Author is just attempting to write a provocative, attention getting article. Literally Millions have experienced warped rotors caused by one of these three: 1) Improperly torqued lugs. 2) Encountering water while rotors are hot. 3) Or simply manufacturing defects.

 

you shouldnt but look up how breake rotors are made and you will see that there is no way it gets hot enough to warp. It just cant. there are lots of things that can seem like warping but they are not.

 

I get it, I have a hard time understanding how metal that thick could ever warp or even wear any at all! Seems like they should all last for 60+ years. However, there are tons of things that happen every day that I don't understand..

 

Most often what we consider "warping" is actually uneven deposit of brake pad material on the rotor(s), caused by improperly bedding the new brakes in. I've had this issue before and it was resolved by repeating the bedding in procedure.

In other cases, there can be actual warping based on manufacturing defects in the metal, similar to those that cause cracks in some cross-drilled rotors. I suppose you could experience what feels like warping if the rotor(s) are not installed on an even hub surface. It is imperative that the wheel hubs be cleaned of any rust deposits before new rotors are put on, as it could result in slightly uneven mounting of the rotor(s) which is magnified at higher speed and feels like wobbling.

Brake rotors - especially on German makes - are made of relatively soft metal. This is why when brakes are due, they will typically require new pads AND rotors.