A connection assembly is used to connect a first body to a second body. The first body includes a bore that is coaxial with a first axis, and a retainer opening that extends coaxially with a second axis. The second axis is perpendicular to the first axis and offset relative to the first axis. In addition, a portion of the retainer opening intersects the bore. The second body includes an insertion portion that is disposed in the bore, a fluid passage that extends through the insertion portion and communicates with the bore, and an outer surface of the second body has a channel. The connection assembly employs an elastic retaining pin that retains the insertion portion within the bore. The retaining pin is disposed in the retainer opening such that a portion of the retaining pin resides in the channel, and the retaining pin is self-aligning and self-retaining.