Some air brake chambers have permanently installed cage bolts that have to be backed out until they stop in order to cage the brakes, rather than inserting a cage bolt and tightening it down. If there's already a nut + bolt sticking out the back of the chamber, it's probably this style of cage bolt.
#brakes
Wear indicators on brake pads should be oriented so that they're on the leading edge of the brake pad, on the stationary pad (since it wears faster). E.g., if the caliper is on the front of the rotor, the wear indicator should be on the top of the pad.