The cellular determinants of K+ secretion in the principal cell include the intracellular K+ concentration, the luminal K+ concentration, the potential (voltage) difference across the luminal membrane, and the permeability of the luminal membrane for K+.
The average cost for a brake pad replacement, resurface rotors is between $254 to $361. Labor costs are estimated between $182 to $231 while parts are priced between $72 to $130.
As a rough guide, rotors should cost about $75 apiece, front pads about $110, rear pads about $60, labor to replace pads about 1 hour per SET of two wheels (a bit more for the back, 1.2) and each rotor removed takes about .2 of an hour.