Singer 491D - The Oil Pump

TO REMOVE
1. Loosen the two oil pipe clamping sleeve nuts A2, Fig. 18.
2. Remove the three screws B2, Fig. 17.
3. Remove the screen frame, screen and oil pump cover C2, Fig. 17,
4. Remove the locking screw D2, Fig. 18.
5. Remove the impeller E2, by turning it over toward the RIGHT (clockwise) to
loosen it, as instructed in Fig. 18.
CAUTION: The impeller E2 is designed to be screwed to the shaft by means
of a LEFT-HAND THREAD and must be turned over toward the right to be loosened.
Avoid damage to this impeller, as the efficient automatic lubrication of the
machine is dependent upon it.
6. Remove the three screws F2.
7. Carefully pull the oil pump body off the lower end of the upright arm shaft.
TO REPLACE
1. Place oil pump body on underside of machine bed, so that position pins G2,
slip into proper holes in machine casting, as shown above.
2. Replace and securely tighten the three screws F2. Make certain that machine
turns freely as screws are tightened.
3. Carefully replace impeller E2, turning it over toward the LEFT to screw it
on arm shaft (see CAUTION above).
4. Make certain that impeller E2 is not so tight that it will bind arm shaft.
Make certain also that impeller clears both top and bottom of interior of
oil pump body, then lock it in position by means of locking screw D2.
5. Replace pump cover, screen and frame C2 and three screws B2, Fig. 17.
Securely tighter screws B2.
6. Replace two oil pipes in oil pump body, as shown above, and securely tighten
sleeve nuts A2.
THE OIL PUMP
TO LOOSEN
F2
G2
E2
D2
F2
G2
A2
Fig. 18
- 11 -