Brake Burnishing

This is critical to ensure proper brake function after brake reline or other major brake maintenance is performed

APTA Recommended Procedure:

• 10 snubs
• From 20 to 5 MPH
• At approximately 32% decel or every 500’ without stopping
• After the 10th snub‚ make 1 complete stop from 20 MPH

Better Methods:

• 20/20/20 – 20 stops from 20 MPH at 20 PSI‚ or 40 MPH to 20 MPH ten times
• The purpose is to gradually raise the brake temperatures‚ to properly seat all brake components‚ mate the lining to the brake drum to improve contact and to cure the material
• Measure brake drum temperature to ensure proper brake function
• Side to side on same axle should generally be within 25° F
• Steer to rear axle should be within approximately 50° F.  This may vary more due to brake valve specifications‚ suspension component compatibility and retarder function