Mody Pumps MS 252 - Manual (Page 10)

GENERAL OVERHAUL AND OIL CHECK. (THIS APPLIES TO BOTH
MODELS
)
TO CARRY OUT A GENERAL OVERHAUL, IT IS ESSENTIAL THAT A COMPLETE
SET OF TOOLS BE AVAILABLE AS PER TOOL KIT LIST. (LIST IS AVAILABLE
AT THE END OF THE MANUAL).
DIS-ASSEMBLY(REFER DRG.NO.MS/859/00
• IT IS MANDATORY THAT ALL "O" RINGS BE REPLACED WHENEVER A PUMP IS OVERHAULED
OR DISMANTLED. UNDER NO CIRCUMSTANCES SHOULD OLD "O" RINGS BE USED, EVEN IF
THEY SEEM O.K. BE CAREFUL NOT TO SCRATCH SEALING SURFACES. ALWAYS GREASE NEW
“O” RINGS BEFORE INSTALLATION.
• ALWAYS ISOLATE THE UNIT FROM ELECTRICAL POWER BEFORE ATTEMPTING ANY
OVERHAUL.
• THE TRANSPORTABLE VERSION IS SUPPLIED WITH A PUMP BASE REMOVE BASE BEFORE
ANY FURTHER DIS – ASSEMBLY. THE PERMANENT INSTALLATION VERSION IS SUPPLIED
WITH A SLIDING BRACKET FIXED ON THE VOLUTE OF THE PUMP. LAY THE PUMP ON IT’S
SIDE ON A BENCH OR OVER TWO SUPPORTS. TURN THE PUMP SO THAT THE OIL HOLE
FACES DOWNWARDS. USING AN ALLEN KEY UNSCREW OIL PLUG (18) TO DRAIN OIL FROM
THE SEAL CHAMBER. IT IS EASIER TO DRAIN THE OIL IF THE OTHER OIL HOLE CAP
SCREW IS ALSO REMOVED. BE CAREFUL. IF THE SEAL HAS LEAKED, THE OIL CASING
MAY BE UNDER PRESSURE. HOLD A RAG OVER THE OIL PLUG TO PREVENT SPLATTER.
• UNSCREW NUTS (4) AND REMOVE PUMP VOLUTE (21) FROM SEAL HOUSING (17). REMOVE
CAP SCREW (26) AND SPRING WASHER (27). REMOVE LOCKING SPACER (25) AND SLIDE
IMPELLER OF THE MOTOR SHAFT. IF THE IMPELLER IS SLIGHTLY TIGHT USE A WOODEN
MALLET TO TAP THE SAME OFF THE SHAFT. REMOVE KEY (30) AND KEEP ASIDE
CAREFULLY.
• THE LOWER MECHANICAL SEAL IS NOW IN VIEW. REMOVE TRIMMING SPACER (S)(31).
USING A NOSE/CIRCLIP PLIER REMOVE CIRCLIP (32). THE MECH. SEAL ASSEMBLY CAN
NOW BE REMOVED FROM THE SHAFT BY HAND. BE VERY CAREFUL WITH THE SEALING
SURFACES SO THAT THEY DO NOT SUFFER DAMAGE OR GET SCRATCHED IN ANY WAY.
LEAVE THE SEAL SEAT IN THE SEAL HOUSING.
• UNSCREW NUTS (4) HOLDING THE SEAL HOUSING AGAINST THE STATOR CASING AND
REMOVE SEAL HOUSING. USE A WOODEN MALLET TO TAP OFF THE SAME. THE UPPER
MECH. SEAL IS NOW IN VIEW. REMOVE THE SEAL IN EXACTLY THE SAME MANNER AS THE
LOWER MECH. SEAL.
• UNSCREW HEX HD. BOLTS (37) HOLDING THE LOWER BEARING BRACKET (16) AGAINST
THE STATOR CASING. THE COMPLETE ROTOR ASSEMBLY WITH LOWER BEARING BRACKET
AND LOWER BEARINGS CAN BE PULLED OUT FROM THE STATOR ASSEMBLY. THE LOWER
BEARING BRACKET CAN BE REMOVED FROM THE ROTOR BY REMOVING THE BEARING COVER.
THE BEARING CAN NOW BE EXAMINED.
• UNSCREW HEX NUT (4) HOLDING THE PUMP COVER (1) AND PRY OUT THE SAME. REMOVE
THE WIRE CONNECTORS (49) TO SEPARATE THE POWER CABLE FROM THE MOTOR LEADS.
THE WIRE CONNECTORS CAN BE UNSCREWED COUNTER CLOCKWISE TO RELEASE THE SAME.
UNSCREW NUT FOR GROMMET (46) AND REMOVE RUBBER GROMMET (45). REMOVE CAP
SCREW (48) AND PRY OUT UPPER BEARING BRACKET (8).
• THE STATOR IS NOW AVAILABLE FOR ELECTRICAL CHECKS, IF ANY ARE REQUIRED. WE
RECOMMEND MEASURING LINE TO LINE RESISTANCE BETWEEN THE THREE POWER LEGS, A
MEGGING TEST AND IF AVAILABLE A HIGH POT.