Figure A:

Brakes Released

Indicator reference Identifies those brakes not fully releasing due to mechanical or pneumatic problems.  While traveling, indicator functions as a brake chamber seal preventing road spray from entering brake chamber.

Figure B:

Brakes Applied                   

-Stroke within Acceptable range.

Reference is used to determine brake adjustment and balance.

Figure C:

Brakes Applied

Stroke outside of acceptable range.

Indicates ineffective braking, needs maintenance attention.