Air in right brake Caliper

Here is a new one. I keep getting air in the right front brake caliper. It takes about 2 days. 2 rebuilt master cylinders. It is not loosing fluid. No leaks. Only the right and not left. Car stops but pedal is almost to floor. If I had a leak it should shoot fluid out and not let air in, Right? No recalls on this car, I called the dealer. 1996 Cirrus 4 cyl with ABS.