5
18. Bend edges of lock washer over one flat on the lower valve
plate and one flat on the brass lower valve nut.
19. Inspect and lubricate with grease top and bottom
seat ring o-rings (replace if necessary). Mueller Co.
recommends the use of Thred Gard
®
Anti-Seize on threads.
20. Lower main valve into the barrel. Carefully align main valve
assembly with seat ring then thread clockwise into the base
of the hydrant. Hand tighten at first to avoid cross threading.
21. Reassemble wrench to upper stem. Pull up on
seat wrench to ensure main valve is completely closed,
lower support arm, and tighten thumb screw, while
maintaining main valve in the closed position. Turn main
valve assembly clockwise to 100-190 ft-lbs.
22. Remove the seat wrench.
23. Attach brass sleeve to upper stem and lubricate outside to
protect o-ring seals from thread damage.
24. Check the condition of the upper barrel o-ring (Flat gasket
for pre-1997 Centurion hydrants). Replace if necessary.
25. Remove the plastic plug from top of the new bonnet
assembly taking care of the hold down washer and
bonnet o-ring.
