Brakes - Vibration While Braking
Group: 46Number: 05-02
Date: Oct. 3, 2005
Subject:
Customer States "Vibration When Braking"
Model(s):
All with Disc Brakes 2003 > 2006
Supersedes T.B. Group 46 Number 04-02 dated Sept. 9, 2004 due to additional model year and warranty table information change.
Condition
Vibration when braking may be due to brake rotor 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 8000Km (5,000 miles) of vehicle service.
Required Materials
^ 6-inch Dual Action sander (Blue Point(R) Stock No. AT411A) or equivalent.
^ 4 40-grit 6-inch sanding discs (3M(R) Part No. 9184NA) or equivalent (obtain from local supplier).
^ 4 80-grit 6-inch sanding discs (3M(R) Part No. 9183NA) or equivalent (obtain from local supplier).
^ 80-grit sand paper (obtain from local supplier).
^ Micrometer capable of measuring from 7 mm-22 mm.
^ Metric scale capable of measuring from 0 mm-20 mm.
Vehicle Inspection
- Check and adjust tire pressures.
- Accelerate vehicle to greater than 55 MPH.
Note:
Please abide by ALL traffic laws and be mindful of the vehicles around you. Perform all operations at your own risk.
- Apply brakes firmly.
Tip:
Vehicles requiring front rotor 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 rotors.
If vibration is not observed:
- Clean only front rotors.
Service
Disassembly & Inspection
- Remove wheels, disassemble brake calipers and remove brake discs. See appropriate Repair Manual for vehicle you are servicing.
- Mark rotors for reinstallation (Left/Right).
- Mark brake pads for reinstallation (Left/Right, Inner/Outer).
- Inspect all brake components for damage due to outside influence.
- Using micrometer, measure rotor thickness. See appropriate Repair Manual for minimum brake rotor thickness.
Tip:
Affected rotors will have uneven color across the friction surfaces. This will determine on vehicles with EPB if rear rotors need to be sanded.
Rotor Surface Cleaning
Remove remaining corrosion protection coating as follows:
- Sand rotor 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 rotor 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 rotor surface.
- Clean all rotor friction surfaces.
Tip:
Rotors must be free of dust and particles left from the sanding process.
Deglaze and Clean Brake Pads
- Place 80-grit sand paper on flat hard surface.
- Carefully sand brake pad until surface glazing is removed.
- Measure brake pad thickness using metric scale.
If any brake pad is equal to or less than 50% of original thickness of new 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 rotors, brake pads, calipers and wheels. See appropriate Repair Manual for vehicle you are servicing.
- Road test vehicle to confirm vibration concern is corrected.
When procedure applies to vehicles within the New Vehicle Limited Warranty, use the table shown.