AMT 1640-162-90 Mechanical Seal - Buna-N/Carbon/Ceramic Type 6

The AMT 1640-162-90 is a Mechanical Seal, Buna-N/Carbon/Ceramic, Type 6, size 3/4 Inch for an AMT Pump. MECHANICAL SEAL REPLACEMENT
Always replace the seal seat , seal head and shaft sleeve to ensure proper mating of mechanical seal components. 1. Unthread cap screws and remove casing and o-ring from the adapter . 2. Unthread round head screws and remove volute from adapter. 3. Unscrew impeller from the engine shaft. Remove the impeller shim , shaft sleeve and seal head from engine shaft. NOTE: To keep the shaft from turning, remove the shroud from the engine and hold the flywheel in place. 4. Unthread hex flange screw and remove the adapter from the engine mounting face. 5. Push seal seat from the adapter recess with a screwdriver. 6. Clean the adapter recess before inserting a new seal seat. 7. Carefully wipe the ceramic surface of the new seal seat with a clean cloth. 8. Wet the outside of the rubber portion of the seal seat with a light coating of soapy water. 9. Press the new seal seat squarely into the cavity in the adapter. Use finger pressure only to avoid scratching the seal seat . 10. After the seal seat is in place, be sure that it is clean and has not been marred. 11. Using a clean cloth, wipe the shaft and make certain that it is perfectly clean. 12. Secure the adapter on the engine mounting face. Tighten hex flange screws EVENLY to avoid cocking rabbet on engine mounting face. 13. Apply a light coating of soapy water to the inside rubber portion of seal head and slide onto the shaft sleeve. Slip the shaft sleeve with seal head onto the engine shaft with the black carbon face toward the white ceramic seal seat. Do not touch or wipe the face of the polished surface part of the seal head. 14. Replace any impeller shim removed in disassembly. 15. Screw impeller back in place, tightening until it is against the shaft sleeve. 16. Remount volute and position o-ring in place. IMPORTANT: Always inspect o-ring. Replace when cracked or worn. Wet o-ring with soapy water for ease of assembly. 17. Remount casing.