Caging brakes is only done when an air brake system failure has happened and you need to get your unit to a safe haven only, not normal operation. This procedure releases the spring tension within the brake chamber and will render that wheel with no brakes when completed.
I recently had a problem with my air spread axle on my step deck trailer that caused my brake system to lock up on the sliding rear axle. It ended up being a air valve failure that couldn't be fixed on the side of the road anyway. I had to cage the brakes on both sides of my rear sliding trailer axle. Since I was empty, I had enough braking power on the other 4 axles to safely travel to the nearest shop and get repaired. This saved me quite a bit of money for avoiding a service call.
- To do this, crawl under truck or trailer and find brake chamber to the wheel with brakes you want to release.
- On the chamber itself, you'll find the internal hex pipe plug. It'll be mounted on the clamp of the brake chamber. Remove the nut, washer and tool from the holder.
- Remove dust cover from brake chamber
- Insert caging tool into chamber and turn 1/4 clockwise to seat the tool
- Insert washer and nut
- Tighten to about 2.5 inches of caging tool exposed. This is hard work as you'll be compressing that spring by hand.
- At this point, your brakes should be released on that wheel. If not, continue to turn until released
Remember, this procedure is not for normal operation, but to get to a safe haven where repairs can be performed. Stay safe out there!