2
Specifications Information and
Repair Parts Manual
3931-99
BEARING HOUSING SERVICE
1. Remove front pump assembly as
described under “Mechanical Seal
Replacement”
2. Remove shaft bearing (Ref. No. 3)
and shaft (Ref. No. 5) as an assembly
by first removing retaining ring (Ref.
No. 1). Push shaft bearing assembly
out of pedestal (Ref. No. 6) by
rapping on threaded end of shaft
with a rawhide mallet, or block of
wood and a hammer.
3. Ball bearings can now be removed
from shaft.
4. If shaft bearings have been removed
from shaft, replace by sliding
bearing on shaft to shoulder.
Replace shaft bearing assembly by
sliding assembly into housing
threaded end first. Push shaft
bearing assembly completely in by
gently tapping on keyway end of
shaft with a rawhide mallet. Replace
retaining ring.
5. Reassemble pump as described in
“Mechanical Seal Replacement”.
SHIM ADJUSTMENT
1. When installing a replacement
adapter (Ref. No.10), impeller (Ref.
No. 16), shaft sleeve (Ref. No. 14),
volute (Ref. No. 18) or casing (Ref.
No. 20) it may be necessary to vary
the number of impeller shims (Ref.
No. 15) that will be required. This is
easily done by adding one shim
more than was removed and
reassembling pump as described in
MECHANICAL SEAL REPLACEMENT
section.
NOTE:
When adding or removing shims,
it is best to proceed with a 0.010"
increment each time. While tightening
unit together turn shaft; feel for shaft
seizing. If shaft begins to seize before
fasteners are completely tight,
disassemble pump and remove one shim
and repeat assembly.
2. Once having added one shim more
than original, ensure that volute and
adapter are firmly fitted (check
fasteners Ref. No. 17). When pump
shaft turns freely add shims until it
does strike, then remove a 0.010"
shim. This should allow proper
clearance.
3. Proper running clearance for
impeller should be as close as
possible to volute without striking;
maximum clearance is 1/32" (0.032").
4. Follow above procedure until proper
clearance is obtained. This will ensure
maximum performance.
2-Inch Trash Pedestal Pumps
Press in new seal
seat. Use a piece
of cardboard to
protect surface
while installing
Pry out seal
seat with
screwdriver
Carbon face (see
CAUTION below)
Lubricate before
assembly (see step
nos. 8 and 13)
Impeller
Seal seat
Adapter
Pump shaft
Shaft sleeve
Shim(s)
Figure 2 - Mechanical Seal Replacement
Seal head
Maintenance (Continued)