I must say that I do not understand why the calipers don't explode right off the brackets on the A body brakes. Those retainers don't look anywhere near heavy enough to me!!!
The retainers just keep the calipers from falling off when the brakes aren't being applied. When applied, the rotational force of the rotor pushes the caliper into the groove on the leading side of the caliper bracket, and the force is carried in that groove.
Which is also why the sliders are supposedly stronger, because that force is carried by the pins on the pin type brakes.
