LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2017 >> Spark LT, Automatic CVT Trans >> Repair and Diagnosis >> External Pages >> Different car >> Section 72 (Disc Brake System) >> Diagnostic Information and Procedures >> Brake Rotor Assembled Lateral Runout Measurement

Brake Rotor Assembled Lateral Runout Measurement

WARNING: This page is about a different car, the 2019 Buick Cascada, 2018 Buick Cascada, and 2017 Buick Cascada. However, it is still accessible from the selected car via links, so may be relevant.

Special Tools

For equivalent regional tool, refer to Special Tools .

    WARNING:

    Refer to Brake Dust Warning .

    NOTE:
    • Brake rotor assembled lateral runout (LRO) exceeding the maximum allowable specification can cause thickness variation to develop in the brake rotor over time, usually between 4800 and 11300 km (3000 and 7000 mi).
    • Brake rotor thickness variation MUST be checked BEFORE checking for assembled lateral runout (LRO). Thickness variation exceeding the maximum acceptable level can cause brake pulsation. Refer to Brake Rotor Thickness Variation Measurement .
    NOTE:

    Whenever the brake rotor has been separated from the hub/axle flange, any rust or contaminants should be cleaned from the hub/axle flange and the brake rotor mating surfaces. Failure to do this may result in excessive assembled lateral runout (LRO) of the brake rotor, which could lead to brake pulsation.

  1. Inspect the mating surface of the hub/axle flange and the brake rotor to ensure that there are no foreign particles, corrosion, rust, or debris remaining. If the wheel hub/axle flange and/or if the brake rotor mating surfaces exhibit these conditions, perform the following steps:
    1. Remove the brake rotor from the vehicle. Refer to Front Brake Rotor Replacement , and/or Rear Brake Rotor Replacement .
    2. Using the CH-42450-A  resurfacing kit, thoroughly clean any rust or corrosion from the mating surface of the hub/axle flange.
    3. Using the CH-41013  resurfacing kit, thoroughly clean any rust or corrosion from the mating surface of the brake rotor.
    4. Clean the friction surfaces of the brake rotor with denatured alcohol, or an equivalent approved brake cleaner.
  2. Install the rotor to the hub/axle flange.
  3. GM891797

    Hold the rotor firmly in place against the hub/axle flange and install one of the CH-45101-100  washers (1), and one lug nut (2) onto the upper-most wheel stud.

  4. Continue to hold the rotor secure and tighten the lug nut firmly by hand.
  5. GM2027291

    Install the remaining CH-45101-100  washers (1) and lug nuts onto the wheel studs and tighten the nuts firmly by hand in a star-pattern.

  6. Tighten the lug nuts in a star-pattern to specification, in order to properly secure the rotor. Refer to Tire and Wheel Removal and Installation .
  7. If the brake rotor has been REFINISHED or REPLACED with a new rotor, proceed to step 13.
  8. If the brake rotor meets the following criteria, proceed to step 9.
    • The rotor is within specifications and is being REUSED.
    • The rotor has NOT been refinished.
    • The rotor does NOT exhibit thickness variation exceeding the maximum allowable level.
  9. GM2027293

    Mount the CH-45101  gauge (1) or equivalent, to the strut and position the indicator button so it contacts the brake rotor friction surface at a 90 degree angle, approximately 13 mm (0.5 in) from the outer edge of the rotor.

  10. Measure and record the assembled LRO of the brake rotor.
    1. Rotate the rotor until the lowest reading is displayed on the indicator dial, then set the dial to zero.
    2. Rotate the rotor until the highest reading is displayed on the dial.
    3. Mark the location of the high spot relative to the nearest wheel stud, or studs.
    4. Measure and record the amount of LRO.
  11. Compare the brake rotor assembled LRO to the disc brake component specifications. Refer to Disc Brake Component Specifications 
  12. If the brake rotor assembled LRO is within specifications, proceed to step 17.

    If the brake rotor assembled LRO exceeds the specification, refinish the rotor to ensure true parallelism. Refer to Brake Rotor Refinishing . After refinishing the rotor, proceed to step 13.

  13. Mount the CH-45101  gauge (1) or equivalent, to the strut and position the indicator button so it contacts the brake rotor friction surface at a 90 degree angle, approximately 13 mm (0.5 in) from the outer edge of the rotor.
  14. Measure and record the assembled LRO of the brake rotor.
    1. Rotate the rotor until the lowest reading is displayed on the indicator dial, then set the dial to zero.
    2. Rotate the rotor until the highest reading is displayed on the dial.
    3. Mark the location of the high spot relative to the nearest wheel stud, or studs.
    4. Measure and record the amount of LRO.
  15. Compare the brake rotor assembled LRO to the disc brake component specifications.
  16. If the brake rotor assembled LRO measurement exceeds the specification, replace the brake rotors. Refer to Front Brake Rotor Replacement , and/or Rear Brake Rotor Replacement .
  17. If the brake rotor assembled LRO measurement is within specification, install the brake caliper and depress the brake pedal several times to secure the rotor in place before removing the CH-45101-100  washers.
scientia non olet · About LEMON Manuals