Mody Pumps G 902_G906TSS316 - Manual (Page 6)

GENERAL OVERHAUL AND OIL CHECK.
REFER DRAWINGS DWG/047/00 (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.
• UNSCREW BOLTS - 4 NOS. AND REMOVE STRAINER
• LOOSE NUTS - 4 NOS. AND REMOVE DIFFUSER CENTER
• THE IMPELLER IS NOW IN VIEW.
• PULL OUT OUTER CASING AFTER REMOVING DIFFUSER HOLDER.
• LOOSEN IMPELLER LOCK NUT. REMOVE LOCK WASHER AND SLIDE IMPELLER OFF THE KEY
ON THE SHAFT. REMOVE TRIMMING SPACERS AND KEEP ASIDE. UNSCREW THE FOUR PH.
HEAD SCREWS AND REMOVE THE SAND GUARD FROM THE SEAL HOUSING.
• THE SEAL CHAMBER CONTAINS APPROX. 6.5 LITER OF OIL. THE LEVEL AND CONDITION
OF THE OIL SHOULD BE CHECKED EVERY SIX MONTHS. UNSCREW THE OIL PLUGS (45)
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.
• LOOSEN STUD ASSY. TURN LARGE NUT -- COUNTER CLOCKWISE AND UNSCREW THE SAME
FROM LOWER BEARING BRACKET.
• TAP OFF WEAR PLATE.
• THE OIL DIAPHRAGM IS NOW IN VIEW. UNSCREW BOTH THE OIL PLUGS AND DRAIN OUT
THE OIL FROM THE OIL CHAMBER. LOOSEN SCREWS FROM THE OIL BAG RING. TURN OIL
DIAPHRAGM INSIDE OUT AND REMOVE SMALL OIL BAG CLAMP IN THE SAME FASHION.
REMOVE OIL DIAPHRAGM. SLIDE OUT CAP FOR CIRCLIP AND CIRCLIP FROM ROTOR
SHAFT. REMOVE LOWER MECHANICAL SEAL. BE VERY CAREFUL IN HANDLING THE SILICON
CARBIDE SEAL FACE. LEAVE STATIONARY SILICON CARBIDE SEAT IN THE SEAL
HOUSING. UNSCREW FOUR NUTS AND PULL OUT SEAL HOUSING. THE STATIONARY SC 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 SILICON CARBIDE SEAL FACE CAREFULLY. BY MEANS OF TWO SCREW
DRIVERS PRY OUT THE LOWER BEARING BRACKET FROM THE STATOR CASING. THE
COMPLETE ROTOR ASSEMBLY WITH BEARING, BEARING COVER AND STATIONARY SC SEAT
WILL COME OUT AS ONE ASSEMBLY. LOOSEN BOLTS AND REMOVE BEARING COVER. 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 SILICON CARBIDE STATIONARY SEAT IN THE BEARING BRACKET. THE
SC SEAT CAN NOW BE PUSHED OUT BY HAND FROM THE BEARING SIDE. (DO NOT HAMMER
THE SEAT).
• CHECK BOTH UPPER AND LOWER BEARINGS 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 GREASE WHICH ARE AVAILABLE FROM
US READILY).