creamypanda

Is burning smell normal after dealer replaced front brake pads, rotors, and sensors this morning?

Will the smell go away or should I go back and have the dealer look into it?

Thanks!

MB Fanatic

The smell is normal. I just had the rotors and pads on my Acura TL replaced the other day with high performance frozen rotors and pads. The smell goes away after a about 10 semi-hard stops. Just break them in properly.

creamypanda

Thanks! What is the "proper" way to break in new pads/rotors?

Moviela

Pagid is an OEM, and here are their instructions:




BRAKE PAD BEDDING IN PROCEDURE

To ensure maximum performance and customer satisfaction, new brake pads must be bedded in upon installation. Correct bedding guarantees that new brake pads and new rotors work flawlessly together. In order to function optimally, organic brake pads must develop friction coal on its surface. This friction coal develops at a temperature of approximately 280°C (537°F). It is very important that this temperature is reached continuously and slowly. This gradual process generates temperatures that not only penetrate the surface of the brake discs and pads, but also distribute evenly through the whole disc and pad material. This is essential when using new brake discs, since the disc often shows signs of stress (due to the casting process and fast cooling) in the materials. A steady and careful warming and cooling process guarantees a good release of both materials.



The bedding in/break in procedure should be done as follows:

Drive at approx. 35 mph (60 kmh) for about 500 yards (solid front discs) to 800 yards (vented front discs) while slightly dragging the brakes (i.e. light brake pedal pressure). This process allows the brake temperature to slowly and evenly build up to 300°C (572°F).
Now, if possible, drive about 2200 yards maintaining the same speed without braking. This will allow the pads and discs to cool down evenly. After this cool-down, perform a normal brake application from 35 mph to 0. No panic stops!
Now, the friction surface has evenly developed friction coal, the pads have bonded with the disc surface, and tensions in the disc materials will have disappeared.
Only trained master mechanics should perform this procedure before delivering the vehicle to its owner. Do not expect your customer to properly finish your brake job!
This bedding process is only suitable for the front axle - not the rear. This is due to the brake force distribution of front and rear axles. In order to reach 300°C (527°F) on the rear pads you would have to drive several miles with dragging brakes. However, in that time the front brakes will be glowing red, overheating and thus destroying the front brakes.
Final note – don’t forget to clean hubs and check the wheel bearings. Also, the brake fluid should be replaced at least every 2 years.

mleskovar

If your MB is the 'drive by wire' type you cannot apply brakes and gas at the same time....correct? Also...1 mile+ without stopping? Where can you do this in the city or even around your house unless you live in the country. I've seen other variations of pad break in and they all do the same thing - heat pads slowly, don't stop completely until finished with process, then let them cool off.

Moviela

In our neck of the woods, I use Hoover between Bolsa and Westminster. 1 mile.

In Los Angeles 26th Street from Soto to the 710, 3.2 miles, no lights, no stop signs.

In Hong Kong North Lantau Expressway fromTsing Ma Bridge to Tong Chung. 7 miles more or less.

In the case of drive by wire, speed up, brake lightly, while still movig about 10 mph, speed up again.

mleskovar

So how do you get to these places without using your brakes unless you put the pads in right there? The method I learned is to accelerate to 35 mph and apply the brakes to slow the car but not coming to a stop (if possible) if you must come to a stop don't leave your foot on the brake, use the parking brake to hold it there....not hard braking, but with enough pressure to heat things up..... four or five times in succession should be enough. Then stop and let it cool for 1/2 hour....again use parking brake to hold, not foot on the brake. I found most people could do this right around their neighborhood. I bet there's umpteen methods/combinations of recommended pad break in procedures! How many dealers, or even independent brake shops, do you think even bother to break them in?

Moviela

Very light braking during the first 50 miles or so will not "bed" the system. When you arrive, you can heat up the brakes for bedding them.

Your method is also perfectly acceptable. The key being to keep the wheels rolling, and the temperature up.

That is a clever idea to use the parking brake should you need a full stop because of traffic. That works on Mercedes cars because they have a seperate parking brake system, unlike most other cars that have a mechanical connection to the rear wheel brake shoes or calipers.

You are 100% correct, I doubt any dealers do this, and I would bet only race preparation shops are the only ones who do it.

lkchris

Genuine rotors have protective coating not to be washed off but rather scraped off by brake usage. Could create an odor when heated.

New pads require lubrication on backs and edges to combat squealing. Could create and odor when heated.

StapleGun

After the dozens of brake jobs I have performed, I can attest to that being normal for a short duration of breaking in...or your parking brake is on...