Astra L4-1.8L (2009)
Brake Rotor/Disc: Procedures
Brake Rotor Refinishing
Special Tools
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J 21177-A Drum-to-Brake Shoe Clearance Gage
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J 41013 Rotor Resurfacing Kit
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J 42450-A Wheel Hub Resurfacing Kit
Important:
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The disc brake rotors do not require refinishing as part of routine brake system service. New disc brake rotors do not require
refinishing.
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Do not refinish disc brake rotors in an attempt to correct the following conditions:
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Brake system noise - squeal, growl, groan
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Uneven and/or premature disc brake pad wear
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Superficial or cosmetic corrosion/rust of the disc brake rotor friction surface
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Scoring of the disc brake rotor friction surface less than the maximum allowable specification
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Before refinishing a brake rotor, the rotor MUST first be checked for adequate thickness to allow the rotor to be refinished and
remain above the minimum allowable thickness after refinish specification. Refer to Brake Rotor Thickness Measurement (See:
Testing and Inspection/Brake Rotor Thickness Measurement).
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Disc brake rotors should only be refinished if they have adequate thickness to be refinished and if one or more of the following
conditions exist:
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Thickness variation in excess of the maximum allowable specification
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Excessive corrosion/rust and/or pitting
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Cracks and/or heat spots
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Excessive blueing discoloration
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Scoring of the disc brake rotor surface in excess of the maximum allowable specification
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Disc brake rotors may need to be refinished as part of the process for correcting brake rotor assembled lateral runout (LRO) that
exceeds the maximum allowable specification.
1. Remove the relevant wheel.
2. Check the surface condition of the brake disc. Refer to Brake Rotor Surface and Wear Inspection (See: Testing and Inspection/Brake Rotor
Surface and Wear Inspection).
3. Using the J 42450-A , thoroughly clean any rust or corrosion from the mating surface of the hub/axle flange.
4. Using the J 41013 , thoroughly clean any rust or corrosion from the mating surface and mounting surface of the brake rotor.
Important: Once these dimensions have been attained, new brake linings may only be installed on one further occasion. Thereafter, the
brake discs must be replaced. Do not use brake discs which cannot be re-machined within the nominal values.
5. Measure the brake disc thickness with J 21177-A .
6. Mount the brake rotor to the brake lathe according to the lathe manufacturer's instructions, ensuring that all mounting attachments and adapters are
clean and free of debris.
Important: If at any time the brake rotor exceeds the minimum allowable thickness after refinish specification, the brake rotor must be
replaced.
7. After each successive cut, inspect the brake rotor thickness. Refer to Brake Rotor Thickness Measurement (See: Testing and Inspection/Brake
Rotor Thickness Measurement).
