Silverado 1500 2WD V8-4.8L VIN V (2006)
BRAKE ROTOR CLEAN-UP PROCEDURE
Clean-up the rotors on an approved, well-maintained brake lathe to guarantee smooth, flat and parallel surfaces. Check for clean and true lathe adapters
and make sure the arbor shoulder is clean and free of debris or burrs. For more information see the "Brake Lathe Calibration Procedure" section in this
bulletin.
1. On the outboard area of the rotor, position the cutting tools one eighth of an inch into the brake pad area of the rotor. Feed the cutting tools into the
rotor until they cut the rotor to new metal, a full 360 degrees. Zero each dial and back off a full turn.
2. Move the cutting bits to the middle of the rotor and do the same procedure. If zero is passed during the process, reset zero. Back off a full turn.
3. Position the cutting bits one eighth of an inch inside the inboard (closest to the hub) edge of the brake pad contact area. Do the same procedure. If
zero is passed during the process, reset zero.
4. Back off a full turn and position the cutting bits all the way inboard in preparation to refinish the full rotor surface. Advance both tool cutters to the
zero setting plus just enough to clean up the entire rotor surface.
5. After completing the refinish, sand both sides of the rotor for approximately one minute per side using a sanding block and 130-150 grit sandpaper
to obtain a non-directional finish.
Important
Only remove the necessary amount of material from each side of the rotor and note that equal amounts of material do not have to be removed from
both sides on any brake system using a floating caliper.
Important
In many of these instances, such a minimal amount of material is removed from the rotor that customer satisfaction is not a concern for future
brake services. This procedure is intended to "Clean-up" the rotor surface and should be conveyed to the customer as such - not as "cut", "refinish"
or "machine", which tends to be terms understood as a substantial reduction of rotor material/life. If the brake lathe equipment being used is not
capable of removing minor amounts of material while holding tolerances, further lathe maintenance, repair, updates or equipment replacement may
be necessary.
Brake Noise
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 to 4
aggressive stops may temporarily reduce or eliminate most brake squeal. If the noise persists and is consistently occurring, 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 88862181 (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:
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Occurs with front semi-metallic brake pads at medium speeds when light to medium pressure is applied to the brake pedal.
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Occasionally a noise may occur on rear brakes during the first few stops or with cold brakes and/or high humidity.
Grinding Noise:
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Common to rear brakes and some front disc brakes during initial stops after the vehicle has been parked overnight.
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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.
Key Points - Frequently Asked Questions
KEY POINTS - FREQUENTLY ASKED QUESTIONS
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Q: How do on-car lathes react to Axle Float? Does the play affect the machining of the rotor, either surface finish or LRO?
