GORMAN-RUPP AMT 12DC-95, Specifications Information And Repair Parts Manual

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Specifications Information and Repair Parts Manual
12DC-95 & 12DC-98
12DC-250-00 2 4/2021
Washdown Pumps; 12-Volt DC Models
NOTE:
Motor shaft must be held in place to remove impeller.
Back of the motor either has slot in shaft (use large screwdriver to
hold) or has 2 flats on motor shaft (use 7/16 open end wrench to
hold). Impeller and impeller fastener unscrew CCW when looking
at the front of pump.
IMPORTANT: Care should be taken to ensure that the same
number and thickness of shim washers (ref. No. 7) are replaced
behind the impeller as was removed. Shim washers are located
directly behind impeller and become loose as impeller is removed.
4. The seal head can now be pulled from shaft.
5. Pry seal seat from adapter.
INSTALLATION OF NEW SEAL
The precision lapped faces on mechanical seal are easily
damaged. Handle your repair seal carefully. Do not touch
polished seal faces.
IMPORTANT:
Be sure that shaft shoulder does not damage
polished face (see Figure No. 2).
1. Thoroughly clean all surfaces of seal seat cavity in adapter.
2. Using a clean cloth, wipe shaft and shaft sleeve and make
certain that they are perfectly clean.
3. Wet the rubber portion of new seal seat with a light coating
of soapy water. While wearing clean gloves or using a clean
light rag, press seal seat squarely into adapter recess. Use
cardboard washer (usually supplied with new seal), place
over polished surface and use a piece of pipe or dowel rod
to press in firmly but gently. Avoid scratching polished face.
4. Dispose of cardboard washer. Check again to see that
polished face is free of dirt as well as all other foreign particles
and that it has not been scratched or damaged.
5. Wet the inside rubber portion of new seal head with a light
coating of soapy water. Slide head onto motor shaft with
sealing surface facing seal seat (see figure 2).
NOTE:
A short “run-in” period may be necessary to provide
completely leak-free operation.
6. Screw impeller onto shaft. Use screwdriver slot at rear of
motor shaft (oposite the threaded end) to tighten impeller.
NOTE: It may be necessary to remove plug in motor end cap to
expose slot. If removed, be sure to reinstall plug AFTER pump is
completely assembled.
7. Check if shaft turns freely by spinning impeller. If rubbing or
binding is found, remove impeller and add a shim to shaft,
then recheck. Repeat procedure until all rubbing is eliminated.
8. Slide impeller seal onto exposed shaft. Screw acorn nut onto
shaft and tighten.
9. Place casing seal on adapter mounting flange. Attach casing
using bolts being careful not to pinch or “shave” casing seal.
As casing is being tightened, periodically spin impeller to
check for interference with casing.
Seal will produce minor drag when spinning motor shaft, but
rubbing anywhere else must be eliminated! Otherwise, damage to
pump and or motor may occur.
Figure 2 - Seal Installation