Check thickness and condition of brake disks

AR42.10-P-0120MFC

Check thickness and condition of brake disks

08.08.2019

Model

118

1

Brake disk

x

Crack length

 Warning

Risk of injury. Skin or eye injuries may result when handling hot or glowing objects.

Wear protective gloves, protective clothing and safety glasses, if necessary.

AS00.00-Z-0002-01A

 Caution

Risk of injury caused by scraping or cutting body parts on sharp vehicle parts

Always wear protective gloves when working on or near sharp and non-deburred vehicle parts.
Deburr repair panels.

AS00.00-Z-0017-01A

Topical note

Notes on handling, transport and storage of composite brake disks

AH42.10-P-9406-12LF

Notes on safety-relevant components

AH00.00-Z-0019-01A



Remove

1

Remove wheel and tire assemblies.

AR40.10-P-1102MFA



Measure

2

Measure thickness of brake disks (1) on front and rear axles with vernier caliper.

Model 118.303/384
except code U29 (Brake system with larger brake disks on the front axle)
Model 118.303/384
with code U29 (Brake system with larger brake disks on the front axle)
Model 118.344/345/346/347/387Brake disk thickness

*BE42.10-P-1001-09DA

Model 118.303/384
except code 950 (AMG Sports package)
except code U29 (Brake system with larger brake disks on the front axle)
Model 118.303/384
with code 950 (AMG Sports package)
except code U29 (Brake system with larger brake disks on the front axle)
Model 118.303/384
with code U29 (Brake system with larger brake disks on the front axle)
except code 950 (AMG Sports package)
Model 118.344/345/346/347/387
with code 950 (AMG Sports package)
Model 118.344/345/346/347/387
with code U29 (Brake system with larger brake disks on the front axle)
Model 118.344/345/346/347
except code 950 (AMG Sports package)
except code U29 (Brake system with larger brake disks on the front axle)
Model 118.387
except code 950 (AMG Sports package)
except code U29 (Brake system with larger brake disks on the front axle)Brake disk thickness

*BE42.10-P-1001-08FA

 Caliper gauge

*140589001900

If the wear limit has been exceeded or will be exceeded before the next brakepad change.



Replace brake disks (1).

AR42.10-P-0220MFA



Check

3

Check brake disks (1) on front and rear axle for corrosion, score marks, cracks and chippings.

 For perforated brake disks or those provided with sunk holes (1) assess the crack length (x) including the bore diameter.

Model 118.303/384
except code U29 (Brake system with larger brake disks on the front axle)
Model 118.303/384
with code U29 (Brake system with larger brake disks on the front axle)
Model 118.344/345/346/347/387Check brake disks

*BE42.10-P-1002-09DA

Model 118.303/384
except code 950 (AMG Sports package)
except code U29 (Brake system with larger brake disks on the front axle)
Model 118.303/384
with code 950 (AMG Sports package)
except code U29 (Brake system with larger brake disks on the front axle)
Model 118.303/384
with code U29 (Brake system with larger brake disks on the front axle)
except code 950 (AMG Sports package)
Model 118.344/345/346/347/387
with code 950 (AMG Sports package)
Model 118.344/345/346/347/387
with code U29 (Brake system with larger brake disks on the front axle)
Model 118.344/345/346/347
except code 950 (AMG Sports package)
except code U29 (Brake system with larger brake disks on the front axle)
Model 118.387
except code 950 (AMG Sports package)
except code U29 (Brake system with larger brake disks on the front axle)Check brake disks

*BE42.10-P-1002-08FA

If problems exist,



Replace brake disks (1).

AR42.10-P-0220MFA



Install

4

Install wheel and tire assemblies.

AR40.10-P-1102MFA

Check values for front axle brake disks

Number

Designation

Model 118.303/384 except code 950/U29

Model 118.303/384/684 with code 950 except code U29,
model 118.312/387/612/687 except code 950 except code U29,
model 118.603 except code U29

BE42.10-P-1001-08FA

Brake disk thickness

New

mm

24

28

Wear limit

mm

21,4

25,4

Check values for front axle brake disks

Number

Designation

Model 118.303/384 with code U29 except code 950,
model 118.312/314/344/345/346/347/387/612/614/646/647/687 with code 950/U29
model 118.351/603/644/651 with code U29,
model 118.353/354/653/654 with code U29 except code U70

Model 118.314/344/345/346/347/614/646/647 except code 950/U29,
model 118.644 except code U29

BE42.10-P-1001-08FA

Brake disk thickness

New

mm

30

30

Wear limit

mm

28

27,4

Check values for rear axle brake disks

Number

Designation

Model 118.303/384 except code U29

Model 118.303/351/353/354/384/651/653/654 with code U29,
model 118.312/314/344/345/346/347/387/603/612/614/644/646/647/684/687

BE42.10-P-1001-09DA

Brake disk thickness

New

mm

11

12

Wear limit

mm

9,3

10,3

Check values for front axle brake disks

Number

Designation

Model 118.303/384 except code 950/U29

Model 118.303/384/684 with code 950 except code U29,
model 118.312/387/612/687 except code 950 except code U29,
model 118.603 except code U29

BE42.10-P-1002-08FA

Check brake disks

Crack length

Dimension "x"

mm

< 25

< 25

Crack depth

mm

< 0,5

< 0,5

Check values for front axle brake disks

Number

Designation

Model 118.303/384 with code U29 except code 950,
model 118.312/314/344/345/346/347/387/612/614/646/647/687 with code 950/U29
model 118.351/603/644/651 with code U29,
model 118.353/354/653/654 with code U29 except code U70

Model 118.314/344/345/346/347/614/646/647 except code 950/U29,
model 118.644 except code U29

BE42.10-P-1002-08FA

Check brake disks

Crack length

Dimension "x"

mm

< 25

< 25

Crack depth

mm

< 0,5

< 0,5

Check values for rear axle brake disks

Number

Designation

Model 118.303/384 except code U29

Model 118.303/351/353/354/384/651/653/654 with code U29,
model 118.312/314/344/345/346/347/387/603/612/614/644/646/647/684/687

BE42.10-P-1002-09DA

Check brake disks

Crack length

Dimension "x"

mm

< 25

< 25

Crack depth

mm

< 0,5

< 0,5