General Overhaul Information
Tools and Equipment
The following tools and equipment may be needed to overhaul a pump:
1. Usual automotive mechanic's hand tools.
2. An arbor press for assembling or disassembling components.
3. An engine lathe for turning impeller hubs.
4. A suitable hoist and slings.
5. Torque capability up to 325 lb-ft.
While no special tools and equipment are required, a few special items are
illustrated or described so the mechanic can make them or they are
avail•
able from the apparatus manufacturer or the Waterous Company. These
special items are not absolutely necessary, but they will make the
me•
chanic's work much easier.
Preliminary Testing
Before disassembling a pump, test it thoroughly, if possible, and record
the results. A comparison of this test with periodic tests recommended in
form F-1031, Section 1000 can often reveal specific pump troubles.
Ex•
cessive speed, for instance, indicates that impellers and/or wear rings are
probably worn. For a two stage pump in series, excessive speed may
indi•
cate a worn transfer valve or interstage seal, leaking flap valve or a
mal•
functioning relief valve.
Cleaning
The continued satisfactory operation of a pump depends to a great extent
upon the cleanliness of its internal parts. Sand, dirt or other abrasive
mate•
rial will wear gears and related parts. Before disassembling a pump for
repairs, be sure to clean its exterior. Make sure the working space,
benches and tools are clean. Use only clean, lint-free cloths to wipe off
components. Before reassembling a pump or its components, be sure to
clean them thoroughly.
Pump Bodies, Impellers and Transfer Valves
Flush out these components and related parts with clean water. Use a stiff
brush to remove loose scale, caked sediment, etc. Be sure to remove all
traces of old gaskets. Examine pump bodies, covers, adapters and fittings
for cracks, severe corrosion or other damage. Almost all damage to these
parts results from improper use or maintenance, or from freezing. Replace
defective parts.
Bearings, Gaskets, Seals and O-rings
Parts of this nature are frequently damaged during removal or
disassemb•
ly. In addition, they sometimes deteriorate or lose their effectiveness
be•
cause of age or misuse. Replacing these parts whenever overhauling a
pump is a good policy.
Impeller Shafts
Examine shaft for severe scratches, grooves or corrosion - especially
un•
der packing or mechanical seals. If scratches are not severe, and are not
under packing and seals, clean them with a fine-cut file. Grooves are
usu•
ally permissible if they are not sharp or too deep. Even slight longitudinal
scratches will cause leaks and should be removed.
Installing Ball Bearings
Most Waterous pumps are designed so that ball bearings fit tightly on their
shafts and have relatively loose fits in the bearing housings. When
mount•
ing these bearings on shafts, always apply force to the inner races. When
bearings have a tight fit in the housings, and a heavy force is necessary to
install them, be sure to apply force only to the outer bearing races. For
either type of fit, applying force to the wrong bearing race may damage the
balls and race.
Installing Body Gaskets
To provide added sealing for gaskets between bodies and intake adapters,
coat both sides of these gaskets with a suitable sealant. A compound such
as Permatex Super 300 is recommended for this application. Be sure all
traces of previous gaskets and sealant are removed before installing new
gaskets.
End Yoke and Companion Flange Nuts
Do not reuse self-locking nuts. Apply lubrication oil to the threads before
removing. Apply anti-seize to the threads before installing a new self-
lock•
ing nut.
F-
1, Section 4212
Page 8 of 61
