[nobby]

1983 280 SL new front rotors and new performance organic pads all around. MB brake pad paste applied as recommended.
What would cause brake squeal? Do the pads need break in time to eliminate the squeal?
The manual is not real specific on how much paste to use so I used it sparingly. Do I need to apply more?
__________________

 

[GeeS]

Brake squeal has been a mysterious problem for years. Talk to ten different people and you'll get ten different answers. The number one, main thing is that the caliper surface must be immaculate before installing the new pads. Other than that, try brake paste or adhesive, and a couple of good hard brake slams.

 

[nobby]

Brake squeal has been a mysterious problem for years. Talk to ten different people and you'll get ten different answers. The number one, main thing is that the caliper surface must be immaculate before installing the new pads. Other than that, try brake paste or adhesive, and a couple of good hard brake slams.

Thanks, Ron.

 

[isthisdave]

As Ron says, there are as many squeal solutions as there are squeals. Clean rotors and parts is rule # 1. I know you use quality parts and that's rule #2. As to #3, for what it's worth, I was taught that newly installed disc pads need to be 'bedded', or what some may call broken in. It goes something like this; On an appropriate stretch of road accelerate to 20mph and then brake HARD to about 5mph without coming to a complete stop. Repeat at 30mph and 40mph, again without stopping. Then return home using the brakes as sparingly as possible. Allow the brakes to cool before using again. This has worked for me over the years. Dave

 

[nobby]

As Ron says, there are as many squeal solutions as there are squeals. Clean rotors and parts is rule # 1. I know you use quality parts and that's rule #2. As to #3, for what it's worth, I was taught that newly installed disc pads need to be 'bedded', or what some may call broken in. It goes something like this; On an appropriate stretch of road accelerate to 20mph and then brake HARD to about 5mph without coming to a complete stop. Repeat at 30mph and 40mph, again without stopping. Then return home using the brakes as sparingly as possible. Allow the brakes to cool before using again. This has worked for me over the years. Dave

ALRIGHT!! A science project!

Thanks, Dave......I need to drive it some more.....maybe I put 5 kms on it the other day. If it doesn't clear up I will try it.

 

[isthisdave]

ALRIGHT!! A science project!

Glad to help. Don't forget to convert my U.S. spec mph parameters to ROTW (Euro) kph values. Don't want to risk upsetting the time space continuum. Or crashing into Mars.

BTW, not as fond of the new sig.....ha

 

[nobby]

Glad to help. Don't forget to convert my U.S. spec mph parameters to ROTW (Euro) kph values. Don't want to risk upsetting the time space continuum. Or crashing into Mars.

BTW, not as fond of the new sig.....ha

The sig refers to
http://www.benzworld.org/forums/r-c107-sl-slc-class/1314314-loosening-smog-pump-2.html#post2331115

My favorite comment of the week.

 

[isthisdave]

Yeah, I saw that as it happened. Wasn't there a beer commercial about gusto, back in the day?

 

[Djenka018]

What would cause brake squeal? Do the pads need break in time to eliminate the squeal?

If you look carefully at instructions on how to assemble brake cylindres/replace pads you will note that pistons do not have flat surface pushing the pads. The reason? Very much to eliminate sqeals and squeeks from pads. Copper of brakes compound help reduce noise further but it alone cannot do the job.

Will upload later extract from manual.


RE: brakes breaking (in), I would not reccomend using procedure described above as you easily MAY burn pads and thereafter nothing will make them brake nice nor noise free.
When new pads go onto decent rotors (with sign of wear) usualy you have to trim the top and bottom edge of the pad and use breaks gently (very bad performance at forst) until such time they become very effective (usualy after few "breaking kilometres")

 

[ussun]

I fogot mine use to squeek like birds at every stop but since I got the new calipers I haven't heard a churp. Knock on wood.

 

[acarter53]

I worked in a auto repair shop when i was in school. One of the old techs use to wash the rotors with soap and water to prevent the squeel. I do this every time i do a brake job and it works. :thumbsup:

 

[nobby]

The process that isthisdave refers to is "bedding". I did a little research since I started this thread because, as it turns out, everyone has a different opinion and/or home remedy.
Bedding is accomplished just as isthisdave explained. The purpose is to get the pads and rotors hot enough that pad material transfers and inbeds itself to the rotors and also flashes off any lingering adhesives/reducers/thinners that may still be in the pad.
I have now also heard of another procedure along the same lines where you drive your car while applying brakes until they heat up and then let cool down.

And thank you all for reminding us that CLEAN = GOOD.

 

[acarter53]

True

You need to transfer pad material to the Rotor asap. :thumbsup:

 

[nobby]

You need to transfer pad material to the Rotor asap. :thumbsup:

Thanks for the advice.

Even if the car is parked?



Just kidding.

 

[Djenka018]

Here's instruction on caliper pistons

 

[nobby]

Here's instruction on caliper pistons

I appreciate that, djenka, however I did not touch the pistons nor did I remove the heat shield. I basically re and re the pads. Before no squeal...after squeal.

 

[Djenka018]

I appreciate that, djenka, however I did not touch the pistons nor did I remove the heat shield. I basically re and re the pads. Before no squeal...after squeal.

That does not guarantee they are in right position!

However, you may blame it on bad compound for pad, pads "burnt" with hard breaking before bedding, rough disc surface etc... I'd say get another set of pads from different manufacturer and see the results. Worst case you'll end up with 2 sets of pads but they do not require water/bread until next replacement time.

 

[nobby]

I "bedded" the brakes today. It eliminated some of the squeal but the rears still make some noise. The rotors in the front are new but I reused the rotors in the rear. I think I might just pull out the pads in the rear again and apply a lttle more paste.

 

[isthisdave]

I "bedded" the brakes today. It eliminated some of the squeal but the rears still make some noise. The rotors in the front are new but I reused the rotors in the rear. I think I might just pull out the pads in the rear again and apply a lttle more paste.

Nobby, Did you machine the rear rotors?

 

[BenzToy]

Nobby, Did you machine the rear rotors?

Good point. A flat surface is good for new pads.