Suburban 3/4 Ton 2WD V8-350 5.7L (1985)
To replace rotors (both)
.7 hr
Chart 1
Good contact is important between the friction surfaces of the brake system. With semi-metallic linings, it is important to have good refinished rotor
surfaces. A poor finish on one rotor can result in reduced brake effectiveness. This may result in a brake lead condition if installed opposite a properly
finished rotor. The original equipment new disc brake rotors have an initial surface finish of 20 to 60 microinches and aB have a non-directional swirl
pattern.
Service Recommendation
Rotor refinish requires a micro-inch surface refinish equivalent to the new vehicle rotor specification.
The recommended procedure for obtaining this finish is as follows:
Rough Cut
Finish Cut
Spindle Speed
200 RPM
200 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
Optional*
*
Duplication of new rotor and smoother finish for best initial brake effectiveness.
When installing new rotor from service stock "do not" refinish the surface as these parts are to recommended finish. When refinishing brake rotors 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.
^
Adaptors must be clean and free of nicks.
^
Lathe finish cuts should be further improved and made non-directional by dressing rotor surface with a standing disc power tool (AMMCO Model
8350 Safe Swirl Disc Rotor Grinder or equivalent).
^
Rotor surfaces are to be refinished to 20 to 60 micro-inch.
To become familiar with the required surface finish, drag a 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.