| Subject: | Squeak Noise On Brake Apply |
| Models: | 2004-2007 Buick Rainier |
| 2007-2008 Cadillac Escalade, Escalade ESV, Escalade EXT |
| 2007-2008 Chevrolet Avalanche, Silverado, Suburban, Tahoe |
| 2004-2008 Chevrolet Trailblazer, Trailblazer EXT and Trailblazer SS |
| 2005-2007 Chevrolet Silverado Classic with RPO JF3 or JF7 |
| 2004-2008 GMC Envoy, Envoy XL and Envoy XUV |
| 2007-2008 GMC Sierra, Yukon, Yukon Denali, Yukon XL, Yukon Denali XL |
| 2005-2007 GMC Sierra Classic with RPO JF3 or JF7 |
This PI was superseded to update models and Part Numbres. Please discard PIT3779E.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
Owners may comment of a squeak noise when the brake pedal is applied or released. This noise is normally heard when the brake pedal is slowly applied with the engine on or off but may also occur when the brake pedal is released. The noise may be isolated
to the master cylinder area.
Recommendation/Instructions:
To correct this concern, flush the hydraulic brake system with a new and improved GM DOT 3 brake fluid, Part Number 88862806 (Canada 88862807). Remove as much of the old brake fluid from the master cylinder as possible and refill with the new fluid.
Use the proper "Hydraulic Brake System Bleed" procedure in SI and flush out the old brake fluid. After completing the bleed procedure, fill the brake master cylinder reservoir to the maximum fill level with the new brake fluid.
Note: The noise may not be completely eliminated after the flush procedure. It may take several brake applies before the noise is completely eliminated.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
