Ford 2003 Mustang Workshop Manual page 3202

4. Using the special tool, push the shaft seal onto the A/C compressor shaft until seated.
5. Install the shaft seal snap ring.
6. Carry out the A/C compressor external leak test. For additional information, refer to Component
Tests in Section 412-00 .
7. Install the shaft seal felt.
8. Install the A/C clutch hub spacer.