AMT 1640-161-96 Mechanical Seal - Buna-N Type 21

The AMT 1640-161-96 is a Mechanical Seal, Buna-N, Type 21, size 5/8 Inch for an AMT Pump. MECHANICAL SEAL REPLACEMENT
Always replace both seal seat and seal head to be sure proper mating of components! Also, impeller seal should be replaced anytime impeller fastener has been removed. 1. Unthread fasteners and remove pump casing , casing seal and flapper valve from adapter . 2. Unthread fasteners and remove volute from adapter. 3. Remove impeller fastener, impeller seal and impeller . 4. Shaft sleeve and seal head can now be pulled from shaft. IMPORTANT: Care should be taken to be sure that the same number of shim washers are replaced behind impeller as were removed. These shim washers are located directly behind impeller. These washers as well as impeller key become loose as impeller is removed. NOTE: Some motors use an open end 7/16 wrench across flats on rear of motor shaft to prevent shaft from turning. Other motor shafts have a screwdriver slot instead of flats. 5. Unscrew fasteners . Remove mounting base and handle and adapter from motor mounting face. 6. Push seal seat from back of adapter recess with a screwdriver. 7. Clean adapter recess before inserting a new seal seat. The precision lapped faces on mechanical seal are easily damaged. Handle your replacement seal carefully. 8. Carefully wipe polished surface of new seal seat with a clean cloth. 9. Wet rubber portion of seal seat with a light coating of soapy water. 10. Press new seal seat squarely into recess in adapter. If seal seat does not press squarely into cavity, it can be adjusted in place by pushing on it with a piece of pipe. Always use a piece of cardboard between pipe and seal seat to avoid scratching polished surface. 11. After seal seat is in place, be sure that it is clean and has not been marred. NOTE: If removed, slide slinger washer onto shaft until it is located approximately 1/8 from face of motor bearing hub. 12. Using a clean cloth, wipe shaft/shaft sleeve and make certain that it is perfectly clean. 13. Secure foot and handle and adapter on motor mounting face. Carefully guide motor shaft through seal seat. 14. Replace shaft sleeve and impeller key . IMPORTANT: Before installing new shaft sleeve, apply a bead of nonhardening, pliable sealant to motor shaft shoulder. 15. Wet inside rubber portion of new seal head with a light coating of soapy water. Slide head onto shaft/shaft sleeve. Seal head and seal seat will meet. Reinstall any shims which have been removed. . 16. Install impeller and reassemble pump. 17. A short run-in period may be necessary to provide completely leak-free seal operation.