Several important factors are frequently overlooked when performing brake service.
The following list must be considered and followed when appropriate:
- Proper machining of brake rotors is not a simple operation. Make sure
the brake lathe is well maintained. Keep it clean at all times. Handle attachment
hardware with care. Damaged hardware will not machine rotors or drums accurately.
Inspect closely the surface finish of machined rotors and drums. Make sure the cutting
tips remain in good condition. Use a dial indicator to make sure rotors turn squarely
on the brake lathe.
- Keep all installed brake parts as clean as possible. Make sure to clean
machined brake rotors and brake drums with a spray solvent, Saturn Choke Cleaner
P/N 21007127 or Saturn Brake and Choke Cleaner P/N 21007432 or equivalent.
Always wipe off machined brake rotor surfaces with a lint-free shop towel after cleaning.
- Thickness variation of rotors due to wear is a major cause of brake pulsation.
Using a micrometer, check for excessive thickness variation whenever a customer comments
on brake pulsation.
- Lateral rotor runout and restricted brake pads, together, are the leading
cause of uneven brake rotor wear. Therefore, this combination leads directly to brake
pulsation.
Important: Make sure calipers slide freely on their pins. Make sure brake pads move freely
in their brackets.
- Uniform wheel nut torque is very important. Uneven torque can distort brake
rotors, causing excessive lateral brake rotor runout. A hand-held torque wrench must
be used to secure wheel nuts using a crisscross tightening pattern.
Tighten
Tighten the nuts to 140 N·m (103 lb ft)
- After the rotors/drums and the brake pads/shoes have been replaced, proper
break-in promotes longer life, smoother braking, and quieter operation. To obtain
proper break-in, follow this procedure: