Disc Brakes and Pads
Repair Procedures
Inspection
Check the pads for excessive wear, the discs for runout and wear, and the calipers for fluid leakage.
Front Brake
Inspect Front Brake Disc Thickness
Inspect the brake pads for wear and discoloration.
Inspect the brake disc for damage and cracks.
Remove all rust and contamination from the surface, then measure the disc thickness at 8 points at equal distances (5 mm) from the outer edge of the brake disc.
Front brake disc thickness
- Standard: 22 mm (0.8661 in)
Service Limit: 20.4 mm (0.8031 in)
Runout: Less than 0.005 mm (0.0002 in.)
If wear exceeds the allowable limit, replace the left and right discs and pads as a set.
Front Brake Pad Inspection
Check pad wear. Measure the pad thickness and replace it if it is less than the specified value.
- Standard: 11 mm (0.43 in.)
Service Limit: 2.0 mm (0.0787 in)
Make sure that grease is applied to the sliding contact points. Check the pads and backing plates for metal damage.
Inspect Front Brake Disc Runout
Position a dial indicator approximately 5 mm (0.2 in.) from the outer edge of the brake disc and measure disc runout.
Brake Disc Runout
Limit: 0.04 mm (0.0016 in) or less (new)
If brake disc runout exceeds the specified limit, replace the disc, then measure runout again.
If runout does not exceed the specified limit, reinstall the brake disc rotated 180°, then check brake disc runout again.
If runout cannot be corrected by changing the position of the brake disc, replace the brake disc.
Rear Brake
Inspect Rear Brake Disc Thickness
Inspect the brake pads for wear and discoloration.
Inspect the brake disc for damage and cracks.
Remove all rust and contamination from the surface, and measure the disc thickness at no fewer than 8 points at equal distances (5 mm) from the outer circle of the brake disc.
Brake Disc Thickness
-Standard: 10 mm (0.39 in)
-Service Limit: 8.4 mm (0.33 in)
-Deviation: Less than 0.01 mm (0.0004 in)
If wear exceeds the allowable limit, replace the left and right discs and pads as a set.
Rear brake pad inspection
Check pad wear. Measure the pad thickness and replace it if it is less than the specified value.
Pad Thickness
-Standard Value: 10 mm (0.393 in)
- Service limit: 2.0 mm (0.0787 in.)
Make sure that grease is applied to the sliding contact points. Check the pads and backing plates for metal damage.
Inspect Rear Brake Disc Runout
Position a dial indicator approximately 5 mm (0.2 in) from the outer edge of the brake disc and measure disc runout.
Brake Disc Runout
-Limit: 0.05 mm (0.002 in) or less (new)
If brake disc runout exceeds the limit, replace the disc, then measure the runout again.
If runout exceeds the specified limit, reposition the brake disc by turning it 180°, then re-check the brake disc runout.
If runout cannot be corrected by changing the position of the brake disc, replace the brake disc.
Rear Drum Brake
Raise the rear of the vehicle and make sure it is securely supported.
Release the parking brake and remove the rear brake drum.
Inspect the wheel cylinder (A) for leaks.
Inspect the brake shoes (B) for cracks, glazing, wear and contamination.
Measure the thickness of the brake lining (C) on the shoe.
Lining Thickness
Standard: 4.5 mm (0.177 in.)
Service limit: 1.0 mm (0.039 in.)
If the brake lining thickness is less than the service limit, replace the brake shoes as a set.
Check the wheel hub bearings for smooth operation. If necessary, replace them.
Measure the inner diameter of the brake drum with a caliper.
Brake drum inner diameter
Standard: 203.2 mm (8.0 in.)
Service limit: 205.2 mm (8.079 in.)
Brake drum out-of-round
Maximum limit: 0.06 mm (0.00236 in.)
If the brake drum inner diameter exceeds the service limit, replace the brake drum.
Inspect the brake drum for scoring, grooves and cracks.
Inspect the brake shoe and drum for proper contact.
Inspect the outside of the wheel cylinder for excessive wear and damage.
Inspect the backing plate for wear or damage.
Test yourself
A quick Kia Rio YB quiz: every answer comes with an explanation and a link to the manual page.