I have a campy record grupo, and my problem is with the rear brake. Every time I apply it, which is seldom, especially given the problem , the right lever and pad come in to the wheel,and then spring back. however the left side lever comes into the wheel, but doesn't spring back to its original position, essentially moving the entire unit. it then rubs against the wheel. I have tightened the frame screw and tried the centering adjustment screw, to no avail, it almost seems like the position of the brake cablewhich is in a fairly tight arc coming off the top tube is putting pressure downward on the whole brake unit. anyone with a similar experience and any suggestion, short of taking it to the lbs- i might also mention it just came back from a tune up, obviously they didn't notice it.

Could be the cable, but most likely it's the centering over the rim. Loosen the rear nut, centre the brakes and tighten the nut WITHOUT ROTATING THE BRAKE. Easier to do with Shimano brakes as they have flats on the sides of the centre-bolt to let you hold the brake stationary while tightening the nut. On the Campy, you can rotate the brake slightly towards left side so there's extra room, then tighten the rear nut. You'll see that the tightening action will rotate the the brake towards the right side and centre the brakes evenly. On some brakes, I've had to hold the brake with the right pad all the way touching the rim while tightening the centre-bolt nut.