Finish Thompson UC - Manual (Page 15)

15
Impeller Bushings
Removal
1. Remove the impeller (item 3, 3A) according to the steps listed in the section Impeller
Assembly, Removal.
2. Place the impeller drive assembly (items 4,4A, 4B, 4C) on an arbor press with the front of
the impeller drive facing down.
3. Insert a 1” diameter arbor into the bore of the impeller drive assembly. See figure 30.
4. Press on face of rear impeller bushing until (2) bushings (item 4A) and
(1) spacer (item 4B) have been removed. Check for excessive wear. See figure 17.
5. Check the impeller bore for signs of plastic melting or fretting wear.
Replacement
1. Place a piece of tubing with an ID of 1 ¼” at the rear center of the impeller drive assembly.
See figure 31. This tubing protects the lip that the bushing stops against. Place the impeller
and impeller drive assembly in an arbor press with the suction side up.
2. Start the rear bushing into bore of impeller while lining up slots inside of the bushing with
the drive ribs in the bore of the impeller. The interrupted face end of the bushing should
be facing down. Press the bushing into the bottom of the impeller bore with a 1” diameter
figure 30
figure 31
soft-faced arbor. The bushing slides in easily in the beginning of the bore, then becomes tighter. The bushing spacer can then be
placed in the bore of the impeller on top of the first bushing.
3. The front bushing can then be installed as in step #2. The interrupted face of the bushing should be facing up. The front bushing
will slide easily into place. A small portion of the rear impeller bushing projects out of the impeller bore. This is normal.
4. Reinstall the impeller according to the steps listed in the section Impeller Assembly, Replacement.
Power End Reassembly
See section Assembly of Pumps without Motors, steps 1-7.
Pump End Reassembly
1. Take the pump casing (item 1) and lay it suction side down on a clean flat sur face. See figure 32.
2. Insert the shaft’s (item 5) rounded end into the round hole in the shaft support (item 2) in the
casing. See figure 33.
3. Carefully place the impeller and impeller drive assembly (items 3A, 3,4,4A, 4B, 4C) on the pump
shaft. See figure 34. Slowly rotate the impeller assembly and impeller drive assembly to ensure
that there is no binding or dragging.
CAUTION: Do not use steel/iron tools near the magnets. These tools are attracted to the
strong magnetic force and could damage them upon impact.
4. Install a new o-ring (item 12) in the barrier assembly’s (item 6) o-ring groove. Lubricate the
o-ring with a suitable lubricant. See figure 35.
5. Slide the barrier assembly over the shaft and impeller assembly. Align the square hole in the
barrier assembly with the square end of the shaft. Press down on the barrier assembly until it is
fully seated. See figure 36.
figure 32
figure 33
figure 34 figure 35 figure 36