OOSC, Part II, Item 1. Brake Systems, a.(2)(c) and b.(2)(c) - 1/16" Voids in Brake Linings

We recently had a officer write up a brake lining violation on a Level VI inspection. The carrier challenged the violation and said it was not a violation at all. I sent the photos and description of the violation to Part B Instructors, Level VI instructors, and I believe it eventually made it to the Vehicle Committee Chair and/or other members of the vehicle committee. They were split about 50/50 on whether or not the lining was in violation. The lining was cracked but was not over 1/16 inches wide. Many people considered it a violation but not an North American Standard (NAS) OOS condition. There was a separation between the lining and the shoe that exceeded 1/16 inches but the lining was not loose. Several seasoned inspectors said the gap met the defective lining conditions outlined in item (i) of the North American Standard Out-of-Service Criteria (OOSC).

I see a couple of issues of importance: 1) Is a crack in a brake lining a violation or does the crack have to meet the OOSC before it is a violation? Inspectors in the field need this clarified. 2) In the OOSC section (i) says, "Lining cracks or voids that exceed 1/16 inch in width observable on the edge of the lining." Is a separation between the shoe and the lining considered a void if the lining is not loose? The current wording is open to interpretation. This is the second time I've had to deal with the "void" issue.

The Vehicle Committee needs to clarify two issues: 1) Can a brake lining be in violation and not meet the OOSC condition? If not, this needs to be clarified in Part B training and in the OOSC. 2) Section 1. Brakes (2)(c)(i) of the OOSC needs to be rewritten to define what constitutes a "void". Example: Separation of the lining material from the shoe in excess of 1/16 inch or a crack in the lining in excess of 1/16 inch in width. 3) The left side graphic at the bottom of the page OOSC should be clarified with labels. Some of the cracks/voids in the picture appear to be less than 1/16 inch in width and less that 1 1/2 inches in length. This creates confusion for the inspector at the roadside.