Out-of-adjustment brakes and other brake system violations make up almost half of the out-of-service roadside inspection violations on commercial vehicles.

The first part of making sure that a vehicle’s brake system is in good condition takes place before the vehicle leaves the yard. This involves a check of the brake system’s components and functioning during all preventive maintenance. Under this approach, any time the vehicle is in for scheduled maintenance or for any repair, the brake system is checked by a qualified technician.

The inspection should include the “at the wheel” components, including:

• The slack adjuster for condition and free play

• All connecting hardware (clevises, jam nuts, pins, connecting rods, etc.) for looseness, damage, and excessive wear

• The brake chamber for leaks, mounting, and condition

• The airline(s) supplying the chamber for condition, cuts, wear, and rubbing

• The brake linings/pads for wear

• The brake drum or rotor for wear and cracks

The technician should also conduct an operational check of the overall system, including that:

• The system does not leak air

• The low-air warning indicators function

• The parking/emergency brake system will activate should air pressure fall below minimums

• The “tractor protection valve” (unique to tractor-trailers) functions correctly

The other part of maintaining a good brake system is to train drivers on how to correctly inspect the brakes. This includes visually inspecting the “at the wheel” components discussed above, such as the brake chamber, the airlines going to the chamber, the pushrod, connecting hardware, the shoes/pads, and the drums/rotors.

During the walkaround portion of an inspection, the driver should also check all of the airlines, tanks, hoses, and fittings that he/she can see. Drivers need to know how to check all of these components, what to look for, and what is considered “passing and failing.”

Training should also involve teaching drivers how to conduct a “system check” that includes a leak check, a check of the low-air warning device, a test of the emergency brakes, a check of the compressor build-up rate, a check of the parking brakes, and a rolling check of the service brakes.

If maintenance experts are inspecting the brakes during all preventive maintenance checks and drivers are doing a good job with their daily inspections, the brake system should pass inspection – whether it’s Brake Safety Week or at any other time.

For a detailed white paper on how air brakes work, what can go wrong and how to keep them working properly, click here.

Betty Weiland is the senior manager of editorial for transportation at J.J. Keller & Associates. Article used with permission.