I was changing the front brake pads on my '97 Camry yesterday. When I got the caliper off I realized the dummy in PepBoys gave me the wrong pads. So I went back and exchanged them but by the time I got back it was dark out. So I got my trusty worklight out and tried to finish the job. While installing the new pads one of the little springs popped out and went flying it was no where to be found. Are these springs neccesary for safe braking? I will replace them as soon as I can, but I am nervous to drive the car. Also is it OK to remove the whole cylinder to change the pads or should I just take one bolt out and swivel it?

I would consider them as necessary and would replace the lost one before driving the car. They are not that expensive.

Yes, if you are just replacing the pads and not resurfacing or replacing the rotors, you can remove the bottom caliper bolt and swing the caliper up and tie it out of the way.

Mike