Magazine for the auto service professional
Issue link: http://asp.epubxp.com/i/684411
34 | ASP June 2016 Technical many times the actual hub/bearing assembly is the root issue, not the rotor. All the other components and parts After all the cleaning, lubricating and installation of the new abutment pad hard- ware, the bracket is ready to be installed back on the spindle over the cleaned and run-out- checked rotor. Te fasteners require proper torque, thread locker materials and in some cases replace- ment. Be aware that some bracket fasteners are of the torque-to-yield style and will need to be replaced. Stay away from the use of anti-seize. Other components that will need to be installed such as pad anti-rattle clips should be replaced if not part of the actual brake pad. Te same goes for any pad separators. Pad separators or those spring-like pieces that are either attached to the pad or are part of the abutment pad shim aren't found on every vehicle but they are becoming more common. Tese isolate noise-causing vibrations and also serve to push the pad back just far enough to increase fuel economy, increase pad wear and lower pad temperatures. Tey are just strong enough to push the pad back slightly without afecting the brake pedal feel. Again, after being involved in many heat cycles, these springs lose tension and need to be changed. Brake pad shims are also subject to heat cycles, rust and corrosion. Tey can wear out and can separate from the brake pad. Tey need to be replaced and lubricated with the correct lubricant following the manufacturer's instructions. Vibration dampers (Ford loves using these on their rear caliper assemblies) are also becoming more common and they have to be properly reinstalled or replaced if damaged. The road test Burnishing in the new pads is just as important as all the other steps that we have so carefully performed. Tis is a job that shouldn't be left to the customer. Proper burnishing of the pads involves about 10 stops from 40 mph down to 15 mph under gentle and easy brake pressure (not a panic stop that burns the pads and glazes the rotors), allowing the pads to cool between applications. Tis procedure allows for proper pad-to- rotor brake material transfer and will provide optimal brake performance. If the new pads are not properly bedded to the rotors, pedal fade and noise can be a concern. Finishing up I am sure that many of you have skipped more than a few of these steps over the years and managed to get away without any issues. But with things getting lighter and smaller with every model, the smallest vibration or noise is now easily felt and heard, especially after the customer has paid you and had no noises before the brake job was performed. It's the same as most things — we always tend to take time to fgure it out the second time. But if we pay a bit more attention to a few steps along the way, we can usually avoid countless issues that rear their heads and involve a comeback that we end up fxing for free. ■ Jeff Taylor boasts a 31-year career in the automotive industry with Eccles Auto Service in Dundas, On- tario, as a fully licensed profession- al lead technician. While continuing to be "on the bench" every day, Jeff is also heavily involved in govern- ment focus groups, serves as an accomplished technical writer and has competed in internation- al diagnostic competitions as well as providing his expertise as an automotive technical instruc- tor for a major af termarket parts retailer. This brake pad has experienced drastic wear as a result of shims that have oxidized and separated, subjecting the pad to vibratory movement.