Mody Pumps G 556 T - Manual (Page 8)

DISMANTLING AND OVERHAULING
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GENERAL OVERHAUL AND OIL CHECK. (REF.DRGS.NO.DW/131//00 SHEET 1&2)
1. ALWAYS REPLACE O-RINGS WITH NEW ONES WHENEVER DISMANTLING AND RE-ASSEMBLING
A PUMP. NEVER RE-USE OLD O-RINGS.
2. REMOVE BASE PLATE (76), STRAINER (75), NUT (18) AND DIFFUSER (74). THE
DRAWING SHOWS THESE DETAILS. CHECK BY HAND THAT THE ROTOR SHAFT IS NOT BLOCKED.
3. UNSCREW IMPELLER NUT (73), REMOVE LOCK WASHER (72), AND REMOVE 1ST IMPELLER
(65). SLIDE OFF IMPELLER FROM SHAFT. REMOVE KEY (71) AND KEEP ASIDE. UNSCREW
NUT HOLDING GUIDE PLATE (70) AND PRY OFF GUIDE PLATE. SLIDE OFF SHAFT SLEEVE
(66) FROM ROTOR SHAFT. UNSCREW NUTS HOLDING DIFFUSER 2(18) AND PRY OFF
DIFFUSER. REMOVE SECOND IMPELLER FROM SHAFT AND REMOVE KEY UPPER (64).
4. PLACE THE PUMP ON THE BOTTOM STUDS (62). TAP THE OUTER CASING (68) WITH
NYLON TIPPED HAMMERS TILL IT LOOSENS FROM THE TOP BRACKET (22). SEPARATE THE
OUTER CASING FROM THE TOP BRACKET BY EMPLOYING TWO SCREWDRIVERS AS LEVERS AND
PUSH THE OUTER CASING DOWNWARDS TILL IT STANDS ON THE FLOOR. LIFT THE UNIT BY
THE TIE BOLTS (3) CLEAR OFF THE OUTER CASING.
4. THE SEAL CHAMBER CONTAINS APPROX. 1.5 LITRES OF OIL. THE LEVEL AND CONDITION
OF THE OIL SHOULD BE CHECKED EVERY SIX MONTHS. UNSCREW THE OIL PLUGS (66) 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 FOR FURTHER ACTION.
6. UNSCREW NUTS (18) AND FOUR STUDS (17) AND REMOVE WEAR PLATE (31). THIS CAN
BE EASILY DONE BY INSERTING TWO SCREWDRIVERS BETWEEN WEAR PLATE AND LOWER
BRACKET (15) AND PRYING THE WEAR PLATE LOOSE. ALL THE PUMP PARTS HAVE BEEN
DISMANTLED. REPLACE WORN PARTS. REMOVE SAND GUARD (59) BY UNSCREWING FOUR
CHEESE HEAD SCREWS (74) FROM THE SEAL HOUSING (28).
7. THE OIL DIAPHRAGM (56) IS NOW IN VIEW. UNSCREW BOTH THE OIL PLUGS (66) AND
DRAIN OUT THE OIL FROM THE OIL CHAMBER. LOOSEN SCREWS AND NUTS (35/54) FROM THE
BIG OIL CLAMP (55) AND REMOVE CLAMP. TURN OIL DIAPHRAGM INSIDE OUT AND REMOVE
SMALL OIL CLAMP IN THE SAME FASHION. REMOVE OIL DIAPHRAGM. SLIDE OFF OUTER
RETAINING SPRING (61) FROM ROTOR SHAFT AND REMOVE LOWER MECHANICAL SEAL FROM
ROTOR SHAFT. BE VERY CAREFUL IN HANDLING THE TUNGSTEN CARBIDE SEAL FACE. LEAVE
TUNGSTEN CARBIDE SEAT IN THE SEAL HOUSING (38). UNSCREW FOUR NUTS (65) AND PULL
OUT SEAL HOUSING (38). THE TUNGSTEN CARBIDE SEAL FACE WILL COME OUT WITH THE
SEAL HOUSING. HANDLE THE FACE CAREFULLY. THE UPPER MECHANICAL SEAL IS NOW IN
VIEW. REMOVE THE UPPER SEAL IN THE SAME WAY AS THE LOWER SEAL.
8. REMOVE THE FOUR NOS DEEP SEATED CAP SCREWS (16) THAT HOLD THE LOWER BEARING
BRACKET AGAINST THE INNER CASING. BY MEANS OF TWO NOS SCREWDRIVERS REMOVE THE
LOWER BEARING BRACKET FROM THE INNER CASING (12). THE COMPLETE ROTOR (11) WITH
BEARING (68), BEARING COVER AND TUNGSTEN CARBIDE SEAT WILL COME OUT WITH THE
LOWER BEARING BRACKET. REMOVE BOLTS (70) AND REMOVE BEARING COVER. PULL OUT
ROTOR WITH BEARING FROM LOWER BEARING BRACKET. (IF THIS IS DIFFICULT USE A HAND
PRESS TO REMOVE ROTOR FROM BEARING BRACKET. ENSURE NO DAMAGE TO THE TUNGSTEN
CARBIDE SEAT IN BEARING BRACKET). THE TC SEAT WITH CUP SEAL HOLDER CAN NOW BE
PUSHED OUT FROM THE BEARING SIDE BY GENTLY TAPPING THE SAME. (USE FINGERS OR A
NYLON TIPPED LIGHT HAMMER ONLY).