A number of applications within the Comline brake disc range feature integrated ABS rings. Such designs are prevalent among Citroen and Peugeot vehicles, but there is a common fitment issue with this type of disc that relates to the ABS ring and sensor.
The following Comline bulletin outlines the problem and the simple solution:
When correctly installed there is a defined ‘air gap’ between the ABS ring on the disc and ABS sensor mounted to the vehicle. However, corrosion build-up on and around the mounting point cn push the ABS sensor out of place. When installing a new disc, this removes the air gap and causes the ABS ring and ABS sensor to touch.
It may be possible to visually identify this problem prior to disassembly but there are some other symptoms to watch out for. The first is potential problems with the ABS system when fitting the new disc. Quite simply, if the ring and sensor are in direct contact, they will not function as intended or communicate with the vehicle’s ABS system.
In addition, the mis-located ABS sensor on the mounting point may have caused visible damage to the ABS ring on the disc being replaced. The above image illustrates the typical damage you could expect to see.
1. Remove the ABS sensor from the vehicle.
2. Remove any corrosion from the sensor mounting point. If the sensor is installed within the guide tube, remove the sensor from the tube and remove any corrosion that is present.
3. Check the ABS sensor for damage and replace if required. The original sensor can be safely re-installed if there are no visible signs of damage.
4. Install the new brake disc ensuring correct air gap between the ABS sensor and ABS ring.
5. Check to ensure proper function of vehicle ABS system.