Whats the proper procedure? - Page 2 - PeachParts Mercedes-Benz Forum

Chris W. · #16 01-04-2008, 07:59 PM

I think this is a bit of a "holy war" type subject along the lines of lube oils and filters, but I'll throw in my $0.02. I recently did front rotors and pads on my '95 E300D, with stock hardware from Phil. This time around I decided to follow the basic premise on Stoptech's web site, and so far, so good. I've tried various methods before, and admittedly I was somewhat skeptical of this method, but read on. I figured the worst that could happen would be early "warpage" (Stoptech says rotors don't warp, but you know what I mean) and a new set of pads and rotors wouldn't kill me if this totally failed.

I made sure to clean the rotors before installing, all fingerprints, etc.

After installing and getting things running, I did five 60 - 5 "stops" (I didn't actually stop, which I think is important) with heavy pedal pressure, but not MAX pedal pressure. Between each "stop", I lazily accelerated back to 60, i.e. perhaps 20 -25 seconds. After about the third "stop" I started smelling the brakes, which was expected. At no time did ABS engage. At the 4th or 5th stop, the car started to stop much better, i.e. slow down with much more bite and "vigor" than the previous stops.

And yes, I was definitely smelling the brakes, as expected. So I did 2-3 more hard 60 - 5 "stops" and had to actually back off the pedal pressure a bit because the ABS was triggering, a good sign.

Then I cruised home for 7-8 minutes, giving time for the brakes to really cool, and I actually tried to NOT use the brakes at all (I live in the sticks) on the way home, so as to not deposit any pad material on the rotors. I parked the car and let everything totally cool off, without ever using the brakes (I used the parking brake to actually stop, and released it after the car stopped).

The reason for this procedure is supposedly to burn off the volatiles in the pad binding material and on the surface of the pads, and sort of "mate" the pads to the rotors. Now, 10,000 or so miles later, no issues at all. And I'm not gentle on brakes, I tend to use them hard.

Just my experience, not trying to start a holy war!

Rgds,
Chris W.
'95 E300D, 249K

toomany MBZ · #17 01-04-2008, 10:21 PM

I believe the FSM recommends braking, gently, from 80k (50mph) to 40k (30mph) a few times, letting cool between times.

Bens lover · #18 01-05-2008, 01:03 AM

So now its all done.
New pads,semi metallic TRW.
New front rotors,German Company.
Repack front outer wheel bearings,inner are great.
Re manufactured front R/H,L/H calipers.
New brake sensors.
Road test and followed the procedure from TX76513

Brake Bedding

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

Drive at approx. 35 mph (60 kmh) for about 500 yards (solid front disc's) to 800 yards (vented front disc's) 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 disc's 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

That was this afternoon.
This morning I had to replace all 5 GP's on the 123,that was fun too!
Other then that....All is great!
Have a nice one guy's and again Thank you for all the important input!
Dan
Vancouver BC hey!

Bens lover · #19 06-12-2008, 01:04 PM

Just a little follow up on the brake repairs that were done on the 126 and the 123.
All rotors calipers and pads were replaced on both cars.On the 126,no noise whats so ever Nada!On the 123 brake noise or squeals are very evident!
My parts supplier even gave me 4 new rotors front and rear pads,Ive added the blue paste and same problem again.You can hear this car from a long way coming to you if you touch that brake pedal.I took the pads off again to see if the matting surface was equal all over and it is,I even used a file to remove the edge of the pads all around,but the noise persists!
Reading the threads of this issue and found no new solutions.
What should I do now....Live with it.........DAHHHH NO!

jt20 · #20 06-12-2008, 01:57 PM

Did you remove the rust and foreign debris from the cailper piston? You need an even, consistent application of force from it to the back of the pads.

You could also buff the rotors with sand paper against the grain (outward from the center)

jt20 · #21 06-12-2008, 02:10 PM

Quote:

Originally Posted by Chris W.

I think this is a bit of a "holy war" type subject along the lines of lube oils and filters, but I'll throw in my $0.02. I recently did front rotors and pads on my '95 E300D, with stock hardware from Phil. This time around I decided to follow the basic premise on Stoptech's web site, and so far, so good. I've tried various methods before, and admittedly I was somewhat skeptical of this method, but read on. I figured the worst that could happen would be early "warpage" (Stoptech says rotors don't warp, but you know what I mean) and a new set of pads and rotors wouldn't kill me if this totally failed.

I made sure to clean the rotors before installing, all fingerprints, etc.

After installing and getting things running, I did five 60 - 5 "stops" (I didn't actually stop, which I think is important) with heavy pedal pressure, but not MAX pedal pressure. Between each "stop", I lazily accelerated back to 60, i.e. perhaps 20 -25 seconds. After about the third "stop" I started smelling the brakes, which was expected. At no time did ABS engage. At the 4th or 5th stop, the car started to stop much better, i.e. slow down with much more bite and "vigor" than the previous stops.

And yes, I was definitely smelling the brakes, as expected. So I did 2-3 more hard 60 - 5 "stops" and had to actually back off the pedal pressure a bit because the ABS was triggering, a good sign.

Then I cruised home for 7-8 minutes, giving time for the brakes to really cool, and I actually tried to NOT use the brakes at all (I live in the sticks) on the way home, so as to not deposit any pad material on the rotors. I parked the car and let everything totally cool off, without ever using the brakes (I used the parking brake to actually stop, and released it after the car stopped).

The reason for this procedure is supposedly to burn off the volatiles in the pad binding material and on the surface of the pads, and sort of "mate" the pads to the rotors. Now, 10,000 or so miles later, no issues at all. And I'm not gentle on brakes, I tend to use them hard.

Just my experience, not trying to start a holy war!

Rgds,
Chris W.
'95 E300D, 249K

By doing this you increase wear rapidly (smelling brakes) allowing all the pits in the pad to fill in with brake dust and even out the sharp peaks in the pad surface (micro level).

In addition, the heat tempers the pad and rotor, the pad being stiffer is now prohibited from 'bouncing' along the surface of the rotor at high frequencies that result in the screeching and squealing (for new applications).