Hybrid Direct, 2-3-4 Clutch Assembly
WARNING: This page is about a different car, the 2010 GMC Sierra and 2010 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
HD 234 clutch fluid pressure is exhausted from the rear case assembly, allowing hybrid direct, 2-3-4 clutch spring force to move the hybrid direct, 2-3-4 clutch piston and release the hybrid direct, 2-3-4 clutch plates.