I'm not so sure on that bulb. An 1157 is what most have. Should have two elements. One very bright and one just bright.
On your brake light switches. The front one is on the brake lever. Trace the wires down to where they plug into the harness. Unplug them from the harness. With a jumper, and the key on jump the wires in the harness. This should light the brake light.
The rear is hooked to the brake pivot shaft. If adjusted to tight it will keep the brake light on all the time. To adjust, hold the body, turn the nut. To test just do the same as I described with the front.
If either works by jumping the wires, replace the switch.