Replace Hamilton Sundstrand P/N 778839-13, 778839-14, 778839-19, 778839-20, 778839-37, 778839-38, 816682-1, 840618-2, 880724 carbon bushings with Cook Airtomic P/N AIR22947 Slotted Entry Busing in the High Pressure Shutoff Valve. View PDF on drs.faa.gov ↗

The STC PDF is authoritative: installation instructions, ICA requirements and limitations.