Zenith BB-PEP Series, Original Installation, Care And Maintenance, Page: 10 / 16

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11. Remove Rheo seal, or packing housing, depending on your pump type.
L. INSPECTION OF PARTS
After the parts have been cleaned, they should be inspected for nicks and burrs and stubborn residue. The gears and
the edges of the center plate gear pockets are the most likely areas to be damaged because of the sharp edges. An
illuminated magnifier facilitates the examination.
1. All flat surfaces of plates and gears should be “blocked.” Blocking is the act of rubbing the flat surface of a part
on 400-grit, 500-grit, or 3/0 abrasive paper, which is supported on a machinist’s or inspector’s surface plate. A
few light but firm rubs usually is enough to remove the last of the residue and remove minor metal disturbances.
Remember to use a figure 8 pattern to retain flatness and perpendicularity of holes when lapping plates.
Heavy disturbances or residue on side plates (NOT gear plates!) may require stronger rubbing on 320-grit or
even 240-grit abrasive paper followed by blocking on the finer abrasive. Deep score marks or metal transfer
cannot be removed by blocking, and the surfaces must be ground. When surfaces are ground, care must be
taken to maintain the perpendicularly of the precision ground holes with the inner plate surface.
Gear plates
and B-bearings should never be ground; to do so would reduce the axial gear clearance to the point where
interference might occur when the pump was assembled. Gears should not be removed from the shaft and
arbor. Grinding of gears is not recommended.
2. Gears, shafts, and arbors should be lightly polished on the O.D.
3. Any nicks in the gear teeth should be removed by careful stoning with a fine India oilstone or an Arkansas stone.
4. The edges of gear teeth, bearing holes, and dowel holes may be lightly stoned with a round Arkansas stone to
remove any nicks. Then polish the I.D.’s with a small piece of fine abrasive paper.
5. After all preparation has been completed; remove the abrasive grain and loose residue in an ultrasonic cleaner
or other suitable cleaning method. Abrasive grain is larger in size than the pump’s clearances.
6. At this point, dimensional inspection may be made if desired.