9
P/N O&M-BG2GRINDER
REPLACING GRINDER IMPELLER AND SHREDDING RING
Note: This is the only disassembly operation permitted in the field.
All other repairs must be performed at an authorized service center or the factory.
STANDARD TOOLS REQUIRED:
Standard socket wrench set.
Standard set of open end wrenches.
Hammer.
Vise grip pliers.
Allen head socket set.
Screwdrivers.
Wire brush.
CAUTION
– Disconnect all power and control wires to motor at the control panel before starting
the disassembly operations. Do not rely upon opening the circuit breaker only.
IMPORTANT
– Pump should be sanitized with bleach before starting work.
Pump should be thoroughly cleaned of trash and deposits before starting
disassembly operations.
Wear protective gloves and clothing.
Always use a rag on the impeller when turning to prevent cutting hands on the
sharp edges of the shredding ring.
DISASSEMBLY OF SHREDDING RING AND GRINDER IMPELLER
1. Hold the grinder impeller by prying against the impeller cutting bar and remove the allen head
cap screw from the end of the shaft.
2. Use a large screwdriver in the slot end of the shaft and tap (counterclockwise) on one of the
large cutter vanes with a hammer. Tap in a counterclockwise direction (thread is right hand).
3. If the impeller removes easily, clean and replace if worn.
4. Make sure the pump impeller has not loosened when the grinder impeller was removed. This
can be checked on reassembly of grinder impeller and shredding ring. The tips of the impeller
cutter vanes should extend 1/8” below the bottom of the shredding ring. If the distance is
greater, the pump impeller has loosened. If the distance is less, the shredding ring is not
properly seated.
5. After the volute case has been removed, insert screwdriver in slot end of shaft and tap hammer
against the outer vane of the ductile iron pump impeller (clockwise) to ensure it is threaded tight
against shoulder on shaft.
6. Use large screwdriver to tap stainless steel cutter ring from cast iron volute.
7. Clean all threads with a wire brush and file smooth any nicked threads. Use NEVER-SEEZE or
other graphite compound on threads before replacing grinder impeller.
8. Make sure allen head cap screw in bottom of pump shaft is tight. Make sure the impeller turns
freely by hand after reassembly. Some drag will be present due to the shaft seals. There should
not be any binding or tight spots when turning the grinder impeller.
