Case 500, W5, W5A Loader Service Manual

Table of Content

1. General
2. Engines
3. Fuel System
4. Electrical
5. Steering
6. Power Train
7. Brakes
8. Hydraulics
9. Chassis

Manual Extract: Roosa Master Fuel Injection Pumps 188 Series

Some Case Diesel Engines are equipped with a Roosa Master Model DB Fuel injection Pump, Figure 1. This is an extremely com· pact and precision unit which incorporates a high pressure injection pump, a mechanical variable speed centrifugal type governor, vane type fuel transfer pump and is self lubricated by the fuel.

The function of the fuel injection pump is to deliver accurately metered quantities of fuel under high pressure to the fuel injectors.

This must be done with accurate timing in relation to the engine firing order and for a very definite period of time in relation to load and engine speed requirements.

To meet these rigid requirements, the Model DB Injection Pump is of necessity, manufactured to unusually close tolerances.
While the pump cannot be considered delicate, the precision with which it is manufactured can be compared to that of a fine
watch.

It is therefore doubly important that you take extra precautions to prevent the entry of dust or similar abrasives when you perform service work that involves the fuel injection pump or other components of the fuel system.
Some pumps are equipped with an external factory adjusted torque control screw. This screw, which is wired and scaled to prevent unauthorized changes, provides improved engine lugging ability by delivering maximum torque from rated speed down through peak torque speed.