Air disc brake system drag reduction guide pin and methods for the use and assembly thereof

A method of assembling an air disc brake system comprising:

• inserting a guide pin into a bore of a caliper, wherein the bore has first and second ends, wherein the guide pin comprises an outer bearing surface, and an interior through hole extending between and open at first and second ends of the guide pin, wherein the guide pin comprises a relief passage in fluid communication with the first and second ends of the bore;
• inserting a fastener into the through hole and engaging a mounting feature of a carrier;
• and
• installing a cap on the caliper and closing the second end of the bore.

A guide pin for use in an air brake system comprising:

• longitudinally spaced first and second ends.
• an outer bearing surface comprising longitudinally spaced first and second ends;
• an interior through hole extending between and open at the first and second ends of the guide pin;
• and
• a relief passage in fluid communication with the first end of the outer bearing surface and the second end of the guide pin.