TM  10-3930-643-34 BRAKE  TROUBLESHOOTING  AND  MAINTENANCE.  (cent) 8-10. Treadle Check Valve (S/N 2001 and above). (Sheet 3 of 3) ASSEMBLY 6. Install new preformed packing (4) on seat  (l). 7. Install  new  ring  (3)  and  new diaphragm (2) on body (5). 8. Using a 1-1/8”   socket,  socket  wrench handle and torque wrench, install seat (l). Tighten seat (1) to 45 lb-ft . NOTE Return  M1OA  Forklift equipment  condition. to  original END OF TASK 8-42