The chance of the rotor being worn down with 8200 miles would be very unlikely . I sounds like you may still have a bit of air in the system or the wrong type of brake fluid was used , try using a brake bleeder vacum pump & replace the brake fluid making sure that you use DOT 4 brake fluid & as you draw out the old fluid you can see if there is any air in the line . I use that system to bleed or replace the brake fluid in my bike , car & truck , it is easy to use & you can do all the work by yourself . Your brake fluid should not be worn out @ 8200 mi & replaceing the brake fluid may or may not correct your problem but it will draw any air out & you know the correct fluid is in the system . Most people never think that the brake fluid wears out , but it needs to be changed just like any other fluids , I change the brake fluid on my other bikes around 20,000 mi & my autos around 50,000 mi .:newsmile106:
I dont know what fluid the 03 calls for but the 08 HD touring service manual calls for DOT4 .