Air Disc Brake Preventative Maintenance Inspections A Comprehensive Guide

Learn how to conduct preventative maintenance inspections on air disc brakes for truck safety and longevity. Discover essential steps, including wheels on and off inspections, and understand DOT inspection requirements.

• Air disc brakes require routine preventive maintenance inspections for longevity.
• DOT inspectors focus on brake system basics and caliper inspection for air disc brakes.
• Two types of inspections, wheels on and off, ensure thorough maintenance.
• Wheels on inspection involves checking the caliper, brake chamber, pad wear, and more.
• Wheels off inspection includes a detailed check of the brake assembly, rotor thickness, and caliper components.

In Episode 9 of Road Choice TV, host Justin explores the crucial topic of conducting preventative maintenance inspections on air disc brakes. Air disc brakes may require fewer changes compared to drum brakes, but routine preventive maintenance inspections are vital to ensure their longevity and optimal performance. Justin invites Jay, a technician from the shop, to guide viewers through the steps of these inspections, emphasizing their importance and the frequency at which they should be carried out. The episode covers two types of inspections "wheels on" and "wheels off," each serving specific purposes in maintaining the brakes. This summary breaks down the key points from the episode

• DOT Inspection Focus Due to the nature of air disc brakes, many braking operations occur inside the caliper, resulting in fewer external checkpoints for DOT inspections. However, DOT inspectors primarily focus on essential elements of the brake system. This includes ensuring the caliper is properly mounted, verifying the brake chamber's secure attachment to the caliper, and assessing the condition of the brake pads.

• Wheels On Inspection To conduct a wheels on inspection, the truck should be parked on a level surface with wheel chocks in place and the parking brakes released. Key areas to inspect during this process include the caliper, brake chamber, and the brake adjustment cap. Checking the pad wear indicator is vital to identify potential balance issues. Some air disc brakes feature visual wear indicators for easy assessment. The air chamber inspection involves verifying proper mounting, secure air line fastening, and the cleanliness of breather holes.

• Wheels Off Inspection This more detailed inspection includes all elements of the wheels on inspection. In addition, it provides better access to the brake assembly. During a wheels off inspection, the technician should remove the brake pads and assess their thickness and condition. It's essential to check the pad retainer springs and ensure they are not bent or broken. Another important step is examining the pad strap and rotor to determine the rotor's condition. The minimum rotor thickness to inspect for may vary, but a common threshold is around 37 millimeters. Inspecting the rotor surface for cracks and heat checks is also crucial, as extensive heat checking may necessitate rotor replacement. The inspection concludes with ensuring the caliper slides freely and checking the piston and slide pin boots for damage.

• Guide Pin and Bushing Inspection The inspection process extends to guide pins and bushings. It is necessary to assess lateral guide pin bushing wear by attaching a dial indicator base and checking for excessive movement. Similarly, radial guide pin bushing wear should be examined using a dial indicator. Any readings exceeding acceptable values require the replacement of bushings and guide pins.

• Brake Pad Abutment Areas Minor pad abutment wear is considered normal, but excessive wear that impedes pad movement or engagement necessitates carrier replacement. It is crucial to measure rotor run-out, with an acceptable limit of twenty thousandths of an inch total indicator run-out.

This comprehensive guide to preventative maintenance inspections for air disc brakes ensures truck safety and brake longevity. Regularly conducting these inspections can help identify and address issues before they escalate, contributing to the overall safety and efficiency of the braking system.

For further information on air disc brakes, general braking topics, or specific details on the preventative maintenance inspection process demonstrated in this episode, viewers are encouraged to visit the Road Choice website at roadchoice.com or contact Justin directly at [email protected]. Additionally, individuals can visit their local Road Choice parts counter, which offers nationwide support 24/7, 365 days a year. Don't forget to stay tuned for Justin's next episode, where he delves into troubleshooting common air disc brake problems.

This summary provides a concise overview of the key points discussed in Episode 9 of Road Choice TV, offering valuable insights into the maintenance of air disc brakes for heavy trucks.

All rights reserved. Unauthorized reproduction, in whole or in part is strictly prohibited.