Brakes - Rear Brake Rotational Chirp Noise
TSB 08-20-1110/13/08
REAR BRAKE NOISE - ROTATIONAL CHIRP -
(EXCLUDES HYBRID)
FORD:
2008 Escape
MERCURY:
2008 Mariner
This article supersedes TSB 08-11-2 to update the Service procedure.
ISSUE
Some 2008 Escape and Mariner (Excludes Hybrid) vehicles may exhibit a noise from the rear brakes while coming to a stop. This condition does not affect brake performance. The noise is typically described as a cyclic, scraping, or rotational chirp noise.
ACTION
Follow the Service Procedure steps to correct the condition.
SERVICE PROCEDURE
To better determine if this procedure is applicable, be advised of the following characteristics:
^ The noise this procedure addresses is unlike a typical brake squeak.
^ It is often described as a groan noise or scraping noise which is cyclic and follows wheel speed.
^ Vehicles will usually exhibit the noise at speeds under 20 MPH (32 Km/h).
^ This noise will only be present when the brakes are very warm or hot such as experienced in stop and go traffic.
Vehicles built prior to 6/15/2007 follow both procedures A and B.
Vehicles built after 6/15/2007 perform only procedure B.
NOTE
PERFORMING PROCEDURE B IS THE MOST CRITICAL PART OF THIS REPAIR. ADDING LUBRICANT TO THE WHEEL CYLINDER PISTONS WILL REDUCE FRICTION BETWEEN THE WHEEL CYLINDER PISTON AND ALUMINUM WHEEL CYLINDER WALL ELIMINATING NOISE SOURCE.
PROCEDURE A
1. Replace the rear brake shoes. Refer to Workshop Manual (WSM), Section 206-02.
2. Apply Motorcraft� Silicone Brake Caliper Grease and Dielectric Compound to the contact points between the shoe and the rear backing plate. Ensure grease will not contact brake lining surface.
PROCEDURE B
1. Remove the rear brake shoe return springs brake shoes, and wheel cylinder dust boots. Using your hands, push one piston into the wheel cylinder until the opposite side piston is exposed. Be sure the wheel cylinder piston is extending out beyond the end of the wheel cylinder sufficient to allow complete coverage of the piston surface and piston seal. It is possible and recommended to have the piston cup seal slightly exposed when performing this operation (Figure 1).
2. Apply Motorcraft(R) Silicone Brake Caliper Grease and Dielectric Compound around the wheel cylinder pistons and then repeat procedure for opposite side wheel cylinder pistons. Be sure to pack the grease into the wheel cylinder bore to ensure grease gets back to the piston seal. (Figure 2)
3. Once both wheel cylinder pistons have been lubricated, shuttle the pistons side to side three (3) or more times to distribute the lubricant and ensure smooth movement. (Figure 3)
Parts Block
WARRANTY STATUS: Eligible Under Provisions Of New Vehicle Limited Warranty Coverage
IMPORTANT: Warranty coverage limits/policies are not altered by a TSB. Warranty coverage limits are determined by the identified causal part.
OPERATION DESCRIPTION TIME
082011A 2008 Escape/Mariner: 1.0 Hrs.
Remove The Rear Brake
Shoes, Apply Motorcraft
Silicone Brake Caliper
Grease Following Service
Procedure, Replace The
Rear Brake Shoes If
Necessary (Do Not Use
With 2001BB, 2001B1B)
DEALER CODING
CONDITION
BASIC PART NO. CODE
2200 42
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