Spring 501874701

Found a youtube video that actually had the correct make and model. As per every youtube video, a step was left out. The fork spring needs to go below the pin. That is what clicks when you disassemble the brake from the outer cover.

So, take out the upper pin first, then the pivot nut. The brake handle will slide off. Unscrew the plate screws and pop the bottom of the main spring out. Once tension is off the brake, make sure the elbow is up. Then reassemble: Elbow in front of the big spring in handle, use screwdriver to push fork spring down to insert the pin, use screwdriver to tension main spring, put cover plate back on.

It should make sense when you actually look at the parts.