BODY AS-OIL PUMP 1789041 - Caterpillar

Feedback Spring
To use the pneumatic speed setting control with different air pressure ranges and engine speed settings the feedback spring must be changed.
REMOVE OIL LINE
1. Tube assembly. 2. Plate.1. Remove tube assembly (1) and plate (2) from the governor.
REMOVE PLUG
3. Plug.2. Install one of the bolts for plate (2) into plug (3) as shown and pull plug (3) out of its bore.
FEEDBACK SPRING AND SPEED SETTING PISTON POSITION
3. Plug. 4. Piston. 5. Spring.3. With plug (3) out of the bore, speed setting piston (4) and feedback spring (5) can be lifted out of the bore with a magnet.4. Find the correct feedback spring to use for the air pressure range and engine speed rating from the pneumatic speed control spring chart.5. Install spring (5) in the bore over the speed setting rod.6. Place piston (4) over spring (5) and push it down into the counterbore.7. Install a new seal on plug (3), if the original seal is not in good condition.8. Push plug (3) down in the bore and remove the bolt.9. Put plate (2) in position, and install the three bolts and tighten them to 10 N m (90 lb. in.).10. Install tube assembly (1) on the governor.
Be careful not to get paint or other foreign material down in the bore, as this will affect the control operation.
Speed Range Bellows Adjustment
The bellows is made off-center (eccentric) to the top flange area. The bottom of the bellows has a swivel pin that engages the hole in the end of the speed setting lever. The swivel pin is set off-center (eccentric) to the bottom of the bellows but is in line with the center of the air inlet port in the top of the flange.
SPEED SETTING BELLOWS AND LEVERThere is an index mark (notch) 0.76 mm (.030 in.) deep on the outer face of the bellows flange. The index mark is approximately mid range position when it is turned to the front of the governor (when facing the governor name plate).
SPEED SETTING CONTROL
1. Air inlet port. 2. Feedback spring. 3. Pivot.Control air pressure enters the bellows through air inlet port (1) at the top of the flange. Control air pressure expands the speed setting bellows, which pushes down on the lever at the left of pivot (3), raising the right end of the lever against feedback spring (2). The force of the feedback spring is marked on the end of the spring.When the bellows is turned, the eccentric changes the position of the bellows on the speed setting lever. This changes the length of the lever arm. The lever arm is the distance from pivot (3) to the outer edge of the bellows.When the bellows is turned with the index mark to the right