Equipment Inspections - Brakes

     There is no replacement for physically measuring brake stroke, in order to be sure that it is within the prescribed limits. All tractors and trailers in the fleet are supposed to be equipped with yellow plastic brake stroke indicators, if you spot any of these missing while doing a pre-trip, please make note of it on your inspection sheet so we can get them installed. A brake stroke chart is shown below with common chamber sizes in our fleet.

Chamber Size
Adjustment Limit
Common Axle Position

20 Short Stroke

Round Air Line Ports
1 3/4"
Steer Axle

20 Long Stroke

Square Ports / Plastic Tag
Steer Axle

30 Short Stroke

Round Air Line Ports
Trailer Axles

30 Long Stroke

Square Ports/ Plastic Tag
2 1/2"
- All Truck Drives
- Very few Trailers, but we do have some with long stroke Chambers (i.e. 470, 472, 473, 474, 499)


30 Short Stroke

Short Stroke


30 Long Stroke



Long Stroke Tag

Handy Tip

A very good explanation on how to properly check brake adjustment is available here: CVSA Air Brake Adjustment.pdf

     There is a quick visual “dead give-away” that you have a trailer brake that is way out of adjustment. When looking at an individual brake drum and shoe with your brakes released (red button pushed in), you should not be able to see an excessive air gap between both the brake drum and the brake shoes. In most cases you won’t see any gap at all.

This is what a brake within adjustment looks like:

Here is a brake that is out of adjustment, see the difference in the gap?


Disclaimer: K.A.M. makes no guarantees regarding the accuracy of this information. It is intended for educational and assistance purposes, for the drivers of K.A.M. Trucking Inc.