1-2 Accumulator
WARNING: This page is about a different car, the 2004 Pontiac Sunfire, 2004 Chevrolet Classic, and 2004 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
Second clutch feed fluid exhausts from the 1-2 accumulator, and the fluid exhausts past the #2 checkball and through the 2-3 drive fluid circuit. The 1-2 accumulator feed fluid fills the 1-2 accumulator as the second clutch fluid exhausts.