Service manual

3
G. PUMP DISASSEMBLY
Refer to Assembly Drawing In Back Of Manual
CAUTION
ATTENTION
Read this entire procedure before disassembling pump.
1. Remove drive key (36).
2. Remove capscrews (42) and end cover (15) with O-ring (67).
3. Remove capscrews (17).
4. Remove back cover (63) from shaft (6). Do not permit dowel pin (22) to drop as back cover (63) is removed.
Remove dowel pin (60 from either back cover (63) or square housing (62), whichever is applicable.
Remove and discard
O-ring (84)
NOTE: If back cover (63) will not slide easily off shaft (6), clamp housing (62) in a vise with back cover (63)
free. With a soft-headed hammer, tap alternately on ears of back cover (63) until there is sufficient gap
to insert a wedging device between back cover (63) and housing (62). Pry gap until back cover (63) is
free to slide off shaft (6).
CAUTION
ATTENTION
Take care not to damage either faces that are being pried against or 0-ring (84) with prying
device.
CAUTION
ATTENTION
If back cover (63) did not slide off easily because its bushing (54) was seized on shaft
(6), ball bearing (31) was most likely damaged when cover was pried off, and must be
replaced. If back cover (63) did not slide off easily because it was stuck on counterbore
of square housing (62), ball bearing (31) may not have to be replaced.
NOTE: If back cover (63) cannot be removed without applying excessive force, unit should be returned to Imo for
further disassembly and inspection.
CAUTION
ATTENTION
In next step, ring gear (65), pinion (64) and key (66) will be removed. If ring (65) and
pinion (64) are to be reused, identify them, with a marker or the like, so it can be
determined to which housing they belong (if there is more than one housing in pump)
and which direction face of each gear was positioned in housing. Do not mark with scribe
or punch as this may leave a burr or high spot which could lead to pump damage or
seizure. If key (66) is to be reused, mark it so that it can be assembled into its original
stage and facing its original direction.
5. Remove pinion gear (64) and key (66) from shaft (6) and ring gear (65) from square housing (62).
CAUTION
ATTENTION
If pinion gear (64) will not slide easily off shaft (6), its key (66) is most likely at least partially
sheared. In this case the disassembly cannot be completed in the field without the chance of
damaging other good parts and the unit should be returned to Imo for further disassembly and
inspection.
NOTE: If ring gear (65) will not come out of housing (62), it is most likely seized on its OD and will not
be possible to remove. The pump can still be disassembled with the ring gear (65) left in the housing (62).
6. Remove square housing (62) from shaft (6). Do not permit dowel pin (22) to drop as housing (62) is removed.
Remove dowel pin (22) from either housing (62) or (7), whichever is applicable.