Overhaul

NOTE: Do not refinish brake rotors when performing routine brake maintenance such as replacing worn disc brake pads. Refinish a rotor only under the following circumstances:
1. There is a complaint of brake pulsation.
2. There is scoring greater than 1.5 mm (0.060 inch).

DIMENSION CAST IN
All brake rotors have a dimension cast minimum thickness dimension cast into them. This dimension is the minimum wear dimension not a refinishing dimension. Do not use a brake rotor that after refinishing will not meet the specifications shown on the rotor; always replace it with a new rotor. Accurate control of the rotor tolerance is necessary for proper performance of the disc brakes. Machining of the rotor should be done only with precision equipment. Machining equipment should be serviced on a regular basis following the manufacturer s recommended maintenance procedure.

PROPER TOOLS
When refinishing rotors the attaching adapters tool holders vibration dampeners and tool bits must be in good condition. Always use sharp cutting tool or bits and use only replacement cutting bits recommended by the equipment manufacturer. Dull or worn tools leave a poor surface finish which will affect braking performance. Vibration dampening attachments should always be used when refinishing braking surfaces. These attachments eliminate tool chatter and will result in better surface finish. Make sure these adapters are clean and free of nicks.

NONDIRECTIONAL FINISHING
It is very important that the rotor surface be made nondirectional by dressing the rotor surfaces with a sanding disc tool such as Ammco 8750 Safe Swirl Disc Rotor Grinder, Accu Turn 433179 Nondirectional Swirl Finisher, or equivalent, using 120 grit aluminum oxide sandpaper. Sand each rotor surface with moderate pressure for a minimum of 60 seconds. If the brake lathe is not equipped with an adequate nondirectional finishing tool, an alternate method is to use a sanding block with 150 grit aluminum oxide sandpaper. With the rotor turning at the equipment manufacturer's highest recommended cutting speed, sand each rotor surface for a minimum of 60 seconds using moderate pressure. After the rotor has been sanded, clean each surface with denatured alcohol or a suitable brake cleaner. The finished rotor surface should be as close to that of a new rotor as possible. Failure to obtain the best possible rotor finish may affect braking performance.

NOTE: Refer to your lathe's instructions for all initial setup, cutting procedures and recommendations. Tool required J 37704 Disc Brake Lathe, or equivalent.

Rotor Diameter 278.0 mm (10.945 inch)
Maximum Lateral Runout 0.080 mm (0.003 inch)
Thickness Variation 0.013 mm (.0005 inch)
Maximum Scoring 1.5 mm (0.060 inch)
Rotor Thickness (New) 32.2 mm (1.27 inch)
Minimum Rotor Thickness 31.7 mm (1.25 inch)
Discard Thickness [1] 30.7 mm (1.21 inch)
Minimum Wear Stock 1.0 mm (0.039 inch)

[1] All brake rotors have a discard cast into them. Replace any rotor that does not meet this specification. After refinishing rotor, replace any rotor that does not meet the maximum or minimum thickness after refinish specifications.