Front Or Rear Brake Squeal On Slow Stops - keywords disc front groan noise rear squeak
| Subject: | Front or Rear Brake Squeal On Slow Stops |
| Models: | 2005-2008 Chevrolet Corvette |
This PI was superseded to update correct Z51 brake pad applications. Please discard PIC3320E.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
Some customers may comment that when they apply the brakes, the vehicle exhibits a squeal noise. This squeal noise may be heard coming from the front or rear brakes and typically heard during slow stops. Replacing the pads will only correct the concern for a short time until the pads glaze over again. Burnishing the pads will also provide temporary relief. Refer to SI document 707744 for the burnishing procedure. For the 2007 model year Corvette, the brake systems on Z51 were improved to include a High Compression pad material. This new material will reduce brake squeal however brake dust is likely to increase. Installing these pads on 2005-2008 Corvettes with out Z51 has not been validated and should not be attempted.
Recommendation/Instructions:
Brake noise experienced is considered a characteristic of design. The brake pads mentioned above will reduce but not eliminate brake noise. Please refer to the information below in reference to brake noise taken from bulletin 00-05-22-002J. Cooperate bulletin 00-05-22-002J can be read in its entire form by entering bulletin 00-05-22-002J into SI.
BRAKE NOISE
Some brake noise is normal and differences in loading, type of driving, or driving style can make a difference in brake wear on the same make and model. Depending on weather conditions, driving patterns and the local environment, brake noise may become more or less apparent. Verify all metal-to-metal contact areas between pads, pad guides, caliper and knuckles are clean and lubricated with a thin layer of high temperature silicone grease. Brake noise is caused by a "slip-stick" vibration of brake components. While intermittent brake noise may be normal, performing 3 - 4 aggressive stops may temporarily reduce or eliminate most brake squeal. If the noise persists, a brake dampening compound may be applied to the back of each pad. This allows parts to slide freely and not vibrate when moving relative to each other. Use Silicone Brake Lubricant, ACDelco P/N 88862182 (Canadian P/N 88862496) or equivalent.
The following noises are characteristics of all braking systems and are unavoidable. They may not indicate improper operation of the brake system.
Squeak / Squeal Noise:
| • | Occurs with front semi-metallic brake pads at medium speeds when light to medium pressure is applied to the brake pedal. |
| • | Occasionally a noise may occur on rear brakes during the first few stops or with cold brakes and/or high humidity. |
Grinding Noise:
| • | Common to rear brakes and some front disc brakes during initial stops after the vehicle has been parked overnight. |
| • | Caused by corrosion on the metal surfaces during vehicle non-use. Usually disappears after a few stops. |
Groan Noise:
A groan type noise may be heard when stopping quickly or moving forward slowly from a complete stop. This is normal. On vehicles equipped with ABS, a groan or moan type noise during hard braking applications or loose gravel, wet or icy road conditions is a normal function of the ABS activation.
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.
