Thrush 3500 RPM - Manual (Page 6)

12. NOTE: THE MECHANICAL SEAL IS A PRECISION PRODUCT AND MUST BE
TREATED AS SUCH. DURING REMOVAL GREAT CARE MUST BE TAKEN TO AVOID
DROPPING ANY PART OF THE SEAL. TAKE PARTICULAR CARE NOT TO
SCRATCH THE LAPPED FACES ON THE WASHER OF THE SEALING SEAT. DO
NOT PUT A SEAL BACK INTO SERVICE UNTIL THE SEALING FACES OF THE
WASHER AND SEAT HAVE BEEN LAPPED OR REPLACED.
13. The seal cavity of the bracket (15) should be cleaned of all residues. Make sure the
1/32-inch radius in the seal seat cavity is not damaged during disassembly since a sharp
edge can easily cut the O-ring during reassembly.
14. Remove capscrews (26) and washers (25) to take off support foot (24).
15. Unscrew capscrews (17) and washers (18) to remove bracket (15) from bearing frame
(10).
16. Remove impeller key (14) from the shaft and remove water slinger (66).
17. Unscrew capscrews (3) and remove bearing cap (2). Remove O-ring and retainer ring
(6).
18. Slide out shaft (12) with bearing (7 & 11). Since bearings are press fitted on the shaft,
they will have to be pulled or pressed off the shaft. Remove lip closure seal (5) from
frame and bearing cap if damaged.
REASSEMBLY
1. Press lip closure seal (5) into frame and bearing cap.
2. Press bearings (7 & 11) onto shaft (12). Snap retainer ting (6) into place.
3. Slide shaft (12) with bearings (7 & 11) into frame (10) and place O-ring into place.
4. Fasten bearing cap (2) in position with capscrews (3) and position water slinger (66) on
the shaft.
5. Mount bracket (15) by screwing capscrews (17) and washers (18) into bearing frame (10)
to assure proper alignment. Turn all capscrews in an even amount. Fasten the bracket
support foot (24) by placing washers (25) over capscrews (26) and screwing them into
position.
6. Thoroughly inspect the seal cavity in the bracket for burrs or nicks which could damage
the seat of the seal. APPLY A FILM OF SOAP PASTE OR FLAX SOAP (DO NOT USE
OIL OR GREASE) TO THE SEAT AND O-RING (21).
7. If replacing seal cartridge assembly, remove cardboard spacer and slide assembly (19,
20, 21 & 22) onto shaft (12).
8. If it is not possible to insert seal assembly with fingers, press into place with a piece of
tubing that has the end cut square and matches the sleeve diameter. Tubing should be
slightly larger than the diameter of the shaft. Spring tension will probably prevent the
sleeve from remaining in position axially until the impeller is locked against it.
9. When replacing mechanical seal only (21 & 22) wipe the sealing faces of the seat and
seal washer clean. Lubricate theses surfaces and shaft sleeve (19) with a clean soap
solution. Put seat and O-ring (21) on shaft sleeve (19), smooth side to pump end. Slide
the entire rotating assembly onto the sleeve. Carbon in seal head must mate with seal
seat. Replace snap ring (20). The shaft sleeve with the seal rotating assembly on it may
now be replaced onto the pump shaft. Spring tension will probably prevent the sleeve
from remaining in position axially until the impeller is locked against it.