The brakes on my Specialized road bike were not opening all the way when
releasing the brake levers. At first I thought it was the old brake
cables having corrosion so I replace them, and I also put on a set of
new/used levers, since the springs in the original levers were weak, but
this wasn't sufficient.

Went to a bike shop this morning and the shop was closed but the service
area had an open door and I asked the mechanic about replacement
springs. These are for Dia-Compe Edge brakes that came with the bicycle,
circa 1987.

The mechanic told me to just replace the brake set. I ended up buying a
set of Ultegra 6800 calipers from him, with pads, that he had taken off
a bicycle where the owner was upgrading. At first he wanted to sell me
the whole Ultegra group for $300, which had a FC-6703 triple crank, but
he sold me the brakes only, for $50. This is a much better brakeset than
the original, but really I only needed the springs, I was just in a hurry.

How often should I have to replace brake springs. Since this road
bicycle is about 30 years old I figure that the springs do fatigue over
time.

I think this is what I wanted:
http://www.ebay.com/itm/DIA-COMPE-S-PULL-BRAKE-PART-SPRING-/282571492776?hash=item41ca92cda8:g:LiIAAOSwUFtZaPk c