Case 1526, 1530, 1537 Uni-Loader SkidSteer Service Manual

Description

Table of Content (Service Manual)

1. General
2. Engines
3. Fuel System
4. Electrical
5. Power Train
6. Brakes
7. Hydraulics
8. Mounted Equipment

Manual Extract: Electrical Fuel Pump

The electrical fuel pump is designed with a solenoid which, when energized, causes the movement of a hollow plunger in a cylindrical bore. The plunger stroke i s controlled by a set of interrupter type contact points in the pump electrical circuit. The contact points function in a sealed section containing an inert gas for long point life.
Upon energization of the solenoid, the plunger i s forced down in the cylinder against the plunger spring which i s seated on a closed check valve in the bottom of the bore .. A check valve in the plunger opens permitting passage of the trapped fuel through the plunger.

On the opening of the contacts the solenoid i s de-energized; the plunger spring returns the plunger to the top of the bore at a fixed rate to provide the required pressure. During the upward movement of the plunger, the check valve in the plunger i s closed to move the fuel ahead of it into the fuel system and the check valve in the bottom of the bore i s open to permit passage of fuel into the cylinder for the next cycle.

A pulsation dampener in the top of the pump provides steady operation and even pressure. The pump also incorporates a pressure relief system to assure an immediate return to zero fuel pressure when the ignition i s turned off:
The filter system i s contained in the lower portion of the pump and consists of a filter and magnet.