Brakes - Vibration Upon Braking

Condition
Customer States Vibration When Braking





46 06 02 Aug. 16, 2006 2010245 Supersedes T.B. Group 46 number 05-02, dated October 3, 2005 due to undated information

Technical Background
Vibration when braking may be due to brake disc corrosion protection which has not been completely removed by normal braking

Tip: Type of vibration covered in this Technical Bulletin must be corrected within the first 8000 Km (5,000 miles) of vehicle service.

Production Solution
No production change required.

Service
Vehicle Inspection

NOTE:
Abide by ALL traffic laws and be mindful of the vehicles around you while operating the vehicle.

- Check and adjust tire pressure.
- Accelerate vehicle to greater than 55 MPH
- Apply brake firmly.
-

Tip:
Vehicles requiring front disc cleaning will exhibit vibration.

The following steps apply to vehicles without Electronic Parking Brake (EPB):
- Accelerate vehicle to 30 MPH.
- Carefully apply parking brake.

If vibration IS observed:
Clean all front and rear brake discs.

If vibration IS NOT observed:
Clean only front discs.

Disassembly & Inspection
- Remove wheels, disassemble brake calipers and remove brake disc. See appropriate Repair Manual for vehicle you are servicing.
- Paint mark or scribe brake discs for reinstallation (Left/Right).
- Paint mark brake pads for reinstallation (Left/Right, Inner/Outer).
- Inspect all brake components for damage from outside influences.
- Using micrometer, measure brake disc thickness. See appropriate Repair Manual for minimum brake disc thickness.

Tip:
Affected discs will have uneven color across the friction surfaces. This will determine on vehicles with EPB if rear discs need to be sanded.

Brake Disc Surface Cleaning





Remove remaining corrosion protection coating as follows:
- Sand brake disc surfaces until clean metal is visible using 40-grit sanding disc in a clockwise direction using leading edge of sanding disc (1-2 minute per surface).





Replace sanding disc prior to moving to next brake disc surface. To achieve a crosshatch pattern:
- Repeat sanding process using 80-grit sanding disc in a clockwise direction using trailing edge of sanding disc.

Replace sanding disc prior to moving to next brake disc surface. Clean all brake disc friction surfaces using soap and water solution.

Tip:
Brake discs must be free of dust and particles left behind due to the sanding process.

Deglaze and Clean Brake Pads





- Place 80-grit sand paper on flat hard surface.
- Carefully sand brake pads until surface glazing is removed.
- Measure brake pad thickness using metric scale.

If any brake pad is equal to or less than 50 percent of original thickness of new brake pads (excluding backing plate):
- Replace all 4 brake pads on axle you are servicing.

Tip:
See appropriate Repair Manual for new brake pad thickness dimensions.

Reassembly
- Install brake discs, brake pads, brake calipers and wheels. See appropriate Repair Manual for vehicle you are servicing.
- Road test vehicle to confirm vibration concern is corrected.





Warranty





Required Parts and Tools

Tip:
Part number(s) are for reference only. Always see ETKA for the latest part(s) information.