Sl 320 rear brake sqeal

I recently replaced tha brake pads including the disks. After about 500 miles I am getting an occasional annoying sqeal when applying the brakes moderately. The sqeal appears to be coming from the rear brakes only. I used JURID brake pads which are made by Bendix. Any known tricks to make the sqeal go away? Peter

Reply to
Peter W. Peternouschek
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Yep... scour the brake rotor with emory sandpaper... medium or course... so it look all scruffed up. Then break in that pad again as specified.

From 40MPH... slow the car down very gently to 30MPH... wait 30 sec... repeat again for 3 more time and you are done.

Reply to
Tiger

Since you've also run the pads on the rotors without knocking them down, you may need to use that emory paper on the pads to knock down any glaze that may have formed on them.

Reply to
Rodney T. Grill

I thought that squeal comes from dust on the pads. Not so??

DAS

Reply to
Dori A Schmetterling

Brake squeal can be caused by several things. One common problem is a "crystallized" pad surface. This happens when the pads have overheated during the break-in period, which is usually caused by putting new pads on a worn rotor without first knocking-down the shine on the rotor, or by pads are not secured to the caliper (either with a good system of clips or break paste) and allowed to "chatter". The symptom is usually that moderate pedal pressure causes the squeal, but full or very light pressure will silence it. The easiest way to resolve this problem is to "knock-down" both the rotor and the pads. That is, to sand them emery paper so that the shine is gone. This will provide a new surface for a new break-in period. It is also very important that the pads are secured to the caliper to they cannot chatter. Some modern disc brake systems use clips that secure the pad quite well, but others just have pads that snap into place. If the pad, once attached to the caliper, can be shifted around by hand, then brake paste should be used to secure it.

Brake dust can cause noise if it contains a high amount of metal particles and is allowed to build-up on the pads. This can generally be solved by cleaning the brakes with an appropriate solvent. Some pads are worse about this than others. OEM MBZ pads tend to create a lot of dust, but rarely have a high metal particulate content to cause this problem. Another cause of squeal is that a large piece of metal in the metallic pad becomes exposed as the pad wears. Technically, this would be a defect in the pad, but it's rarely worth the trouble to replace it because it will generally go away as it continues to grind on the rotor.

Reply to
Rodney T. Grill

Squeal mainly come from the tiny gap between the rotor and the pad... when pads are not properly broken in...When you put new pads on and glazed it... it make the pads hard and won't properly mate to the existing rotor surface contour... hence the "gap"... sort of like a whistle.

Reply to
Tiger

Both replies interesting. I had squeal when my car was newer (can't remember the mileage, now 18 000). Merc claimed to have put some sort of paste in but squeal returned. Now it seems to have gone without further action.

DAS

Reply to
Dori A Schmetterling

Eventually as you use it... the rotor will wear to the pad's shape... and hence no squeal... but rotor surface is shitty... not flat.

Reply to
Tiger

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