Mody Pumps M 304 T - Manual (Page 7)

GENERAL OVERHAUL AND OIL CHECK. (ID NOS. ARE FOR MODEL M 304T)
REFER DRAWINGS DWG/114/00 (SHEET 1 & 2) AT END OF MANUAL.
• ALWAYS REPLACE O-RINGS WITH NEW ONES WHENEVER DISMANTLING AND RE- ASSEMBLING
A PUMP. NEVER RE-USE OLD O-RINGS.
• THE SEAL CHAMBER CONTAINS APPROX. 1 LITER OF OIL. THE LEVEL AND CONDITION OF
THE OIL SHOULD BE CHECKED EVERY SIX MONTHS. UNSCREW THE OIL PLUGS (42) AND
POUR OUT SOME OIL. NOTE THAT THE OIL GETS A SLIGHTLY DARKER SHADE, BUT THIS
IS NORMAL AND IS NO CAUSE FOR WORRY. IF THE OIL IS EMULSIFIED BY WATER, THE
SEALS HAVE WORN OUT AND MUST BE REMOVED FROM THE ROTOR SHAFT FOR FURTHER
ACTION.
• UNSCREW BOLTS (72) - 4 NOS. AND REMOVE STRAINER (70)
• LOOSE NUTS (7) - 4 NOS. AND REMOVE DIFFUSER (69).
• THE IMPELLER IS NOW IN VIEW.
• PULL OUT LOWER OUTER CASING (63).
• LOOSEN IMPELLER NUT (68). REMOVE LOCK WASHER (67) AND SLIDE IMPELLER OFF THE
KEY (65) ON THE SHAFT. REMOVE TRIMMING SPACERS (64) AND KEEP ASIDE. UNSCREW
THE FOUR PHILLIPS HEAD SCREWS (56) AND REMOVE THE SAND GUARD (55) FROM THE
SEAL HOUSING.
• LOOSEN STUD ASSEMBLY (62). TURN LARGE NUT PINNED ON STUD -- COUNTER
CLOCKWISE AND UNSCREW THE SAME FROM INNER STATOR CASING (33).
• TAP OFF WEAR PLATE (61).
• THE OIL DIAPHRAGM (60) IS NOW IN VIEW. UNSCREW BOTH THE OIL PLUGS AND DRAIN
OUT THE OIL FROM THE OIL CHAMBER. LOOSEN SCREWS AND NUTS (4 & 57) FROM THE
BIG OIL CLAMP (58) AND REMOVE THE CLAMP. TURN OIL DIAPHRAGM INSIDE OUT AND
REMOVE SMALL OIL BAG CLAMP (59) IN THE SAME FASHION. REMOVE OIL DIAPHRAGM.
SLIDE OUT CAP FOR CIRCLIP (54) AND CIRCLIP (50) FROM ROTOR SHAFT. REMOVE
LOWER MECHANICAL SEAL (49). BE VERY CAREFUL IN HANDLING THE TUNGSTEN CARBIDE
SEAL FACE. LEAVE STATIONARY TUNGSTEN CARBIDE SEAT IN THE SEAL HOUSING (51).
UNSCREW FOUR NUTS (52) AND PULL OUT SEAL HOUSING. THE STATIONARY TC FACE
WILL COME OUT WITH THE SEAL HOUSING. THE UPPER MECHANICAL SEAL IS NOW IN
VIEW. REMOVE THE UPPER SEAL IN THE SAME WAY AS THE LOWER SEAL. PLEASE HANDLE
THE ROTATING TUNGSTEN CARBIDE SEAL FACE CAREFULLY. BY MEANS OF TWO SCREW
DRIVERS PRY OUT THE LOWER BEARING BRACKET (46) FROM THE UPPER OUTER CASING
(32). THE COMPLETE ROTOR ASSEMBLY WITH BEARING, BEARING COVER AND STATIONARY
TC SEAT WILL COME OUT AS ONE ASSEMBLY. SLIDE OFF THE UPPER OUTER CASING AND
THE STATOR CASING (33) IS IN VIEW. LOOSEN BOLTS (40) AND REMOVE BEARING
COVER (42). PUSH OUT ROTOR WITH BEARING FROM LOWER BEARING BRACKET. (IF THIS
IS DIFFICULT, USE A HAND PRESS TO REMOVE ROTOR FROM BEARING BRACKET). ENSURE
THAT THERE IS NO DAMAGE TO THE TUNGSTEN CARBIDE STATIONARY SEAT IN THE
BEARING BRACKET. THE TC SEAT CAN NOW BE PUSHED OUT BY HAND FROM THE BEARING
SIDE. (DO NOT HAMMER THE SEAT).
• CHECK BOTH UPPER AND LOWER BEARINGS (38 & 43) FOR ANY RADIAL OR AXIAL PLAY
OR ANY ABNORMAL NOISE WHILE SPINNING THE SAME. CHECK FOR ANY LEAKAGE OF
GREASE THROUGH THE SHIELD OF THE BEARING. IF BEARING SEEMS WORN OUT OR ANY
GREASE LEAKAGE IS OBSERVED, REPLACE BEARING. (DO NOT USE ANY STANDARD
BEARING PROCURED FROM THE MARKET. THE PUMPS USE A SPECIAL BEARING WHICH IS
PRE-FILLED WITH A SPECIAL HIGH TEMPERATURE GREAS AVAILABLE FROM US READILY).