Brake Squeal – 2007-2009 Mercedes-Benz

Date:	May 26, 2009
Order No.:	P-B-42.10/68c
Supersedes:	P-B-42.10/68b dated May 5, 2009
Group:	42

 

Revision History

Revision	Date	Purpose
c	5/26/09	Applicable Models Updated
b	5/5/09	Applicable Models, Repair Procedure for Front Axle,Parts and Warranty Info. Updated
a	4/6/06	Additional Repair Procedure for Rear Brakes / Parts and Warranty Info. Updated
–	2/27/06	Initial issue

 

SUBJECT:

Model 216.371/376/386, Model Year 2007 – 2009
Model 221.171/176/186, Model Year 2007 – 2009
Brake Squeal

 

If you receive customer reports in the above model vehicles of brake squeal emanating from the front or rear of the vehicle, please perform the applicable procedure(s) below.

 

Front Brake Squeal

1. Remove existing brake pads. Refer to WIS document AR42.10-P-0161SX.
2. Clean brake caliper in the area where the brake pads are positioned.
3. Apply brake pad paste (part no. A001 989 87 51) to both ends of each of the improved replacement brake pad’s backing plates and corresponding mating surfaces within the brake caliper (Figure 1, A and Figure 2, A).

Note:  Do not allow any paste to contact brake pad friction surface or apply paste to any other areas besides those specified.  Immediately remove any excess paste that contacts pad front or back surfaces.

Figure 1

 

Figure 2

 

4. Install the improved brake pads. Refer to WIS document AR42.10-P-0161SX.

Note: The revised front brake pads have entered series production as of 10/2008, and can be identified by the solid shim and 10mm chamfer (Figure 3).

Figure 3

 

Rear Brake Squeal

1. Remove existing brake pads. Refer to WIS document AR42.10-P-0160SX.
2. Clean brake caliper in the area where the brake pads are positioned.
3. Apply brake lubrication (part no. BQ142 0001) to the brake pad guides within the brake caliper mounting anchor (Figure 4, arrows), guide elements of brake pads (Figure 5, arrows), and to the caliper in the area where the outer brake pad is in contact (Figure 6, arrows).

Note: Do not allow any lubrication to contact brake pad friction surface or apply lubrication to any other areas besides those specified.  Immediately remove any excess lubrication that contacts pad front or back surfaces.

4. Install the brake pads that are listed within the parts information table. Refer to WIS document  10-P-0160SX.

Figure 4

 

Figure 5

 

Figure 6

 

Notes Regarding Brake Squeal

Note:  Bed in brake pads in the course of a normal road test.  Do not perform any special bedding procedures.

Note:  Brake squeal does not usually necessitate the replacement of the brake discs.  The only time that the brake disc cannot be entirely ruled out as the cause of brake squeal, is when the disc is heavily scored or seriously warped.  Refer to WIS document AP42.10-P-4258SX.

Note:  A damping plate is glued to the backing plate of the brake pads.  This glued joint must adhere the damping plate to the backing plate across the entire surface area in order to provide effective noise damping.  If the glued joint has become partially or wholly detached and the damping plate can be lifted off as a result, then the brake pads must be replaced.

Note:  If the brake pads exhibit signs of excessive heat (white or red discoloration at the edges), this is due to excessively high thermal stresses on the brakes, perhaps as a result of misuse.  In this case the brake pads must be replaced because satisfactory noise damping can no longer be obtained.

 

Parts Information

Qty.	Part Name	Part Number
1	Brake Pads (front)	A0054207820
1	Brake Pads (rear)	A0044204420
1	Brake Paste (front)	A0019898751
1	Brake Lubrication (rear)	BQ1420001

 

Note:  The following allowable labor operations should be used when submitting a warranty claim for this repair.  This information has been generated on May 26, 2009.  Please refer to Netstar -> Star TekInfo ->  Star Time for the most current labor time allowance.

 

In Case of Warranty

Operation:

Wheels – two, R&R (40-1590)
Brake pads – front, R&R/replace if required (wheels removed) (42-2706)
Brake pads – rear, R&R/replace if required (wheels removed) (42-2851)
Road test, perform (00-9151)

Damage Code	Operation Number	Time (hrs.)	Model Indicator (s)
42114 36	40 1590	0.3 hrs.	AA, AB, AD, DA, DB, DE
	42 2706	0.6 hrs.   0.7 hrs.	AA, AD, DA, DB, DE   AB
	OR
42214 36	40 1590	0.3 hrs.	AA, AB, AD, DA, DB, DE
	42 2851	0.5 hrs.	AA, AB, AD, DA, DB, DE
	AND
	00 9151	0.3 hrs.	AA, AB, AD, DA, DB, DE

 

Note:  If this repair is done in conjunction with other brake services, only the parts can be claimed to warranty.

Note:  This document does not extend warranty beyond the posted limits for brake pads.