MUELLER CO. 107 Series Instructions

Bonnet Repair Kit Instructions

SCREW PIN
HOLD DOWN NUT
OPERATING SCREW
BEARING
SHOULDER
(STEP 14)
STEM NUT
STEM NUT SEAL
WIPER RING
UPPER STEM SEAL
Bold items are included in kit.
CAUTION: In order to properly identify the various "O" rings and gaskets included in this kit,
carefully observe the locations and relative sizes of "O" rings and gaskets as you remove parts
from the hydrant. As old "O" rings and gaskets are removed, match them up with the new ones by
comparing sizes.
1. Remove Bonnet Bolts. Rotate Operating Nut in opening direction to fully open position while
holding Bonnet to prevent it from turning. This lifts Bonnet off Upper Barrel.
2. Rotate complete Bonnet assembly counterclockwise to detach it from upper Stem threads.
Lift off.
3. Remove socket head Screw Pin and lift off combined Operating Nut/Weather Cap.
4. Remove Hold Down Nut. Empty oil from Bonnet.
5. Lift out Operating Screw, Operating Screw Bearing, Anti-Friction Washer and Stem Nut through
top of Bonnet as a unit.
6. Remove Operating Screw Bearing from assembly and replace Bearing Seal.
7. Remove Operating Stem from Stem Nut.
8. Remove Operating Screw Seal and Anti-Friction Washer from Operating Stem.
9. Install new Anti-Friction Washer and new Operating Screw Seal on Operating Stem in that order.
10. Remove Stem Nut Seal (Quad Ring) and Wiper Ring from lower area of Bonnet. Replace both
with new parts from kit.
11. Remove oil from Stem Nut. Refill with Mueller Hydrant Lubricant (approx. 2 oz.) while part is
setting level. Oil level should be at bottom of oval slots in sides of Stem Nut.
12. Insert Operating Screw into Stem Nut taking care not to spill oil. Engage several threads only.
13. Reinstall Stem Nut into Bonnet with lugs engaging grooves in Bonnet.
107 Fire Hydrants
OPERATING NUT/WEATHER CAP
OPERATING SCREW SEAL
BEARING SEAL
ANTI-FRICTION WASHER
OPERATING SCREW
BONNET
BONNET GASKET
UPPER BARREL
STEM
(continued)