Brakes - Vibration/Pulsation Upon Application

46 10 05

October 25, 2010

2015173 Supersedes T.B. V461002 dated February 17, 2010 to add additional models and 2011 model year applicability.





Vehicle Information

Condition

Brake Disc, Pulsation

When applying brakes at highway speeds the following symptoms may occur:

Brake pedal may pulsate

Vibration may be felt in vehicle body

Steering wheel may shake

Technical Background

For brake vibration / pulsation concerns, brake disc machining is now allowed between 6 months / 6000 miles and 12 months /12,000 miles of the warranty in service date.





Note

Production Solution

No production change required.

Service





Note:

Procedure:

Remove wheels and separate brake calipers from carrier as outlined in Repair Manual Group 44 - Wheels, Tires, Vehicle Alignment and Group 46 - Brakes - Mechanical components in ElsaWeb.

Brake Disc Inspection

A detailed brake disc inspection is needed to determine if the brake disc should be machined or replaced. Inspect brake disc friction surfaces on both sides of the brake disc for:

^ Severe discoloration (bluing)

^ High heat surface damage (raised hard spots)

^ Visible cracks

Brake discs showing any of the above described conditions MUST be replaced.

Disc Thickness Measuring





Each brake disc has the minimum allowed thickness cast, stamped or laser-etched into the disc hub.

^ Measure the brake disc thickness in 4 locations using either the Pro Cut International(TM) disc thickness measuring tool Part No. 50-902 or the Hunter Engineering Company disc thickness measuring tool Part No. 25-99-2. Measurements MUST be taken the same distance from the brake disc outer circumference to ensure consistency.





Note

Brake Disc Machining





Tip:





Note:





^ Follow the brake lathe manufacturer's instructions for set-up and machining.

^ Wash the brake disc with a soap and water solution upon completion of resurfacing to remove all machining particles.





^ Re-measure brake disc thickness in 4 locations using either the Pro Cut disc thickness measuring tool Part No.50-902 or the Hunter disc thickness measuring tool Part No.25-99-2, to verify that minimum thickness is still exceeded. If recorded brake disc measurement is less than the minimum thickness, the brake disc MUST be replaced.





Note:

^ Measure brake disc lateral run out using Pro Cut Disc Lateral run out measuring kit Part No. 50-700FC or the Hunter Disc Lateral run out measuring kit Part No.25-128-2 with a dial indicator.

Run out must not exceed 0.1 mm.





Warranty





Required Parts and Tools

No Special Parts required.

Additional Information

All part and service references provided in this Technical Bulletin are subject to change and/or removal. Always check with your Parts Dept. and Repair Manuals for the latest information.