AR42.10-B-0120B | Check thickness and condition of brake disks | 12.02.16 |
Vehicle 688 with Cumbustion engine 904.924, 374.976, 374.979, 374.977, 904.957, 904.918, 904.919, 904.908
B42.10-0430-05
1 Brake disc
Dimensions
A Total thickness of disc
B Wear limit
C Bevel
Condition of the brake disc surface
A1 Crack formation in the form of webs
B1 Cracks heading into the hub center
C1 Ripples on the surface of the disk
D1 Through cracks
a Surface of the ring
b Width and depth of the cracks
Whenever required, replace or amend the brake discs. This should be done in pairs on the discs that act on the same axis. | |||
| Check | ||
1 | Remove the wheels | ||
2 | Measure the thickness of the brake disc (1) | On the front shaft, if the service limit is reached, replace the brake disc. | |
On the rear shaft, if the service limit is reached, replace the brake disc. | |||
3 | Measure the maximum lateral deviation of the brake disc (1) | On the front shaft, if the maximum limit is reached, replace the brake disc. | |
On the rear shaft, if the maximum limit is reached, replace the brake disc. | |||
4 | Check the brake discs (1) for wear and cracks | The formation of cracks in the form of webs (A1) and cracks (B1) heading into the center (75%) of the ring surface and a maximum of 0.5 mm in width and depth are permissible. If the ripples on the brake disc surface (C1) are greater than 1.5 mm, align the brake disc.. | |
If the cracks are continuous across the friction area (D1), replace the brake discs. | |||
5 | Check the roughness of the friction surface of the brake disc(1) | Roughness of the friction surface of the brake disc to the front shaft. | |
Roughness of the friction surface of the brake disc to the rear shaft. | |||
6 | Machine the bevel on brake discs(1) | Front shaft brake discs corner bevel. | |
Rear shaft brake discs corner bevel. |
Test values for front brake disks
Número | Denominação | Front axle 733.880 | Front axle 732.510 | |||
BE42.10-B-1001-08A | Rotor thickness | New | mm | 34,00 | 29,80 ... 30,00 | |
Minimum permitted thickness | mm | 28,00 | 26,00 | |||
BE42.10-B-1002-08A | Rotor outer nominal diameter | mm | 312 | 304 | ||
BE42.10-B-1004-08A | Rotor braking surface coarseness | Rz | 20 | 9 ... 15 | ||
R3z | - | - | ||||
BE42.10-B-1005-08A | Disc outer edge chamfer, after machined | mm | 2 | 3 | ||
degrees | 30 | 45 | ||||
Test values for front brake disks
Número | Denominação | Front axle 733.840/851 | Front axle 733.882 | |||
BE42.10-B-1001-08A | Rotor thickness | New | mm | 29,80 ... 30,00 | 29,80 ... 30,00 | |
Minimum permitted thickness | mm | 26,00 | 26,00 | |||
BE42.10-B-1002-08A | Rotor outer nominal diameter | mm | 323,7 ... 324 | 323,7 ... 324 | ||
BE42.10-B-1004-08A | Rotor braking surface coarseness | Rz | 9 ... 15 | 9 ... 15 | ||
R3z | - | - | ||||
BE42.10-B-1005-08A | Disc outer edge chamfer, after machined | mm | 3 | 3 | ||
degrees | 45 | 45 | ||||
Test values for front brake disks
Número | Denominação | Front axle 733.850 | |||
BE42.10-B-1001-08A | Rotor thickness | New | mm | 29,80 ... 30,00 | |
Minimum permitted thickness | mm | 26 | |||
BE42.10-B-1002-08A | Rotor outer nominal diameter | mm | 304 | ||
BE42.10-B-1004-08A | Rotor braking surface coarseness | Rz | 9 ... 15 | ||
R3z | - | ||||
BE42.10-B-1005-08A | Disc outer edge chamfer, after machined | mm | 3 | ||
degrees | 45 | ||||
Test values for rear brake disks
Número | Denominação | Rear axle 743.498 | |||
BE42.10-B-1001-09A | Rotor thickness | New | mm | 34,00 | |
Minimum permitted thickness | mm | 28,00 | |||
BE42.10-B-1003-09A | Knocking (maximum lateral deviation). Measured 10 mm from outer rotor edge | mm | 0,02 | ||
BE42.10-B-1004-09A | Rotor braking surface coarseness | Rz | 20 | ||
R3z | - | ||||
BE42.10-B-1005-09A | Disc outer edge chamfer, after machined | mm | 2 | ||
degrees | 30 | ||||