Thrush 3500 RPM - Manual (Page 5)

MAINTENANCE
It is doubtful that the THRUSH pump will ever require complete disassembly; generally only
certain components need to be disassembled to accomplish inspection or repair.
DISASSEMBLY
Since the THRUSH base mounted end suction pumps are a back pull out design, it is
unnecessary to disconnect the piping or casing for service. All service and maintenance can be
performed by disconnecting the coupling and removing the power frame assembly from the
casing.
1. Close suction and discharge valves.
2. Break electrical connections to prevent drive unit from being energized during
disassembly.
3. Unscrew two of the pipe plugs (29) from top and bottom of the casing (28). (See Parts
List)
4. Remove all relief, cooling, flushing or drain lines, if present, from the pump.
5. Disconnect the flexible coupling from between the pump and motor. Unscrew the hold
down bolts that hold support foot (24) and bearing frame (10) to base.
6. Remove capscrews (30) from bracket (15) and pull bearing frame bracket assembly from
casing (28). Remove casing gasket (27).
7. Unscrew impeller bolt (35) and remove impeller washer (34), taking care not to damage
gaskets (33 & 36).
8. Slide impeller (37) and impeller key (14) from the shaft, again taking care not to damage
sleeve gasket (23) located behind impeller. Remove sleeve gasket (23).
9. Casing wear ring (39) is pressed into casing (28) with an interference fit and must be
removed with a puller if replacement is necessary.
10. If replacing seal cartridge assembly (19, 20, 21 & 22) slide seal assembly off the shaft.
11. If replacing mechanical seal only (21 & 22) slide assembly off the shaft. Remove snap
ring (20) at spring end. Remove spring and seal head (22). The rubber in seal head may
be partially adhered to shaft sleeve (19). Remove seat and O-ring (21). The sleeve
should be carefully cleaned to remove any residue in seal area, and checked for abrasion
or corrosion. The sleeve under the seal may be polished lightly to 32 RMS finish before
replacing seal assembly (21 & 22). DO NOT REUSE A PITTED SLEEVE.