Full Size Cad RWD V8-350 5.7L DSL (1984)
Brake Rotor/Disc: Technical Service Bulletins
Disc Brake Rotor - Surface Refinish
Bulletin No. T 84-3 File In Group 5
Number
8
Date
Sept. '83
SUBJECT:
DISC BRAKE SURFACE REFINISH
MODELS AFFECTED: ALL MODELS EQUIPPED WITH DISC BRAKES
To meet mandated brake system performance requirements, semi-metallic brake linings have been used for several years in some vehicle applications. In
order to maintain the proper performance, it is important to correctly service these semi-metallic brake systems as follows:
SERVICE RECOMMENDATIONS:
^
Semi-metallic linings should be replaced with semi-metallic service linings.
^
Routine replacement of disc brake linings does not require rotor refinish.
^
Rotor refinish should only be required because of non-parallelism, runout, or deep scoring.
^
If refinishing is necessary, the semi-metallic brakes lining requires a micro-inch surface refinish like the new vehicle rotor specification (10 to 50
micro-inches with nondirectional swirl pattern).
^
The recommended procedure for obtaining this finish is as follows:
Rough Cut
Finish Cut
Spindle Speed
150 RPM
150 RPM
Depth of Cut Per Side
.005"
.002"
Tool Cross Feed Per Rev.
.006" - .010"
.002" Max.
Vibration Dampener
Yes
Yes
Swirl Pattern-120 GRIT
No
Yes
When refinishing brake rotors for semi-metallic linings, the following is important:
^
The brake lathe must be in good working order and have capability to produce the intended surface finish.
^
Use correct tool feed and arbor speeds. Too fast a speed or too deep a cut can result in a rough finish.
^
Cutting tools must be sharp.
^
Adapters must be clean and free of nicks.
^
Lathe finish cuts should be further improved and made non-directional by dressing rotor surface with a sanding disc power tool (AMMCO Model
8350 Safe Swirl Disc Rotor Grinder or equivalent).
^
Rotor surfaces are to be refinished to 10 to 50 micro-inches.
To become familiar with the required surface finish, drag the fingernail over the surface of a new rotor from parts stock or one on a new vehicle. If your
brake equipment cannot produce this smooth a finish when correctly used, contact the equipment manufacturer for corrective instructions.
When installing new rotors from service "do not" refinish the surface as these parts are to recommended finish. It also is not required to refinish a rotor
on a vehicle which has a smooth finish.
