Prizm L4-108 1.8L DOHC VIN 8 MFI (1998)
Technical Service Bulletin # 23-50-05B
Date: 971101
Brakes - Rotor Warranty Service Procedure
File In Section: 5 - Brakes
Bulletin No.: 23-50-05B
Date: November, 1997
INFORMATION
Subject:
Brake Rotor Warranty Service Procedure
Model:
1994-98 GM Passenger Cars
This bulletin outlines GM's procedures for brake rotor service for all applicable GM passenger cars and supersedes Corporate Bulletin Number
23-50-05A Section 5 - Brakes).
Important:
Rotors should only be turned when one or more of the following rotor surface conditions exist:
1. Severe Scoring - depth in excess of 1.5 mm (0.060 in.).
2. Pulsation Concerns from:
a. Thickness variation in excess of 0.025 mm (0.001 in.).
b. Corrosion on rotor braking surfaces.
Rotors are NOT to be resurfaced in an attempt to correct:
1. Noise/squeal.
2. Cosmetic corrosion.
3. Routine pad replacement.
4. Discoloration and/or "hard spots".
Explanation of Brake Rotor Warranty Service Procedure
Research and testing has determined:
1.
Rotor refacing during normal pad replacement is not necessary.
2.
Rotor refacing for cosmetic corrosion is unnecessary. Clean-up of braking surfaces can be accomplished by 10-15 moderate stops from 62-75
km/h (35-40 mph) with cooling time between stops.
3.
Rotor service is ineffective in correcting BRAKE SQUEAL, and/or PREMATURE LINING WEAR OUT, and should NOT be used to address
these conditions.
4.
When installing new rotors, DO NOT reface them.
5.
Ensure bearing flanges are free of corrosion when installing rotors to prevent inducing lateral runout. Use Kent Moore tool J 42450 to clean the
corrosion around the wheel studs.
Brake Service Techniques
EVERY brake service should include:
1.
Clean and lube all metal-to-metal contact points (i.e.; caliper to knuckle, pad to knuckle, etc.).
2.
Clean and lube slide pins.
3.
Set correct clearances - caliper to knuckle, etc.
4.
Clean rotor and hub mounting surfaces. Use Kent Moore tool J 42450 to clean around wheel studs.
Pulsation
Brake pulsation concerns may result from two basic conditions:
1.
Thickness variation.
2.
Excessive corrosion.
