Case 780CK Loader Backhoe Service Repair Manual

Table of Content – Case 780CK Service Manual

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

Manual Extract: Fuel System Removal and Installation of Filter

IMPORTANT: Clean filter head, filters and engine area adjacent to the filters.
1. Close the fuel tank shut-off valve and remove drain plug from the 1st stage filter.
2. Use a clamp type filter wrench or filter wrench, Case No. A64761, Inset A, to remove filters. Turn filters counterclockwise for removal.
3. Remove stud gasket from the 2nd stage filter mounting stud and install a new gasket.
4. Apply a thin film of oil or grease to gaskets on the new 1st and 2nd stage Case Filters. Install filters by turning clockwise until gasket contacts filter head. Hand tighten 1/2 of a turn. Loosen filters and retighten 1/2 to 3/4 of a turn after gasket contact to obtain proper seal.

NOTE: Excessive tightening will damage gaskets and filters.

5. Loosen bail locknut retaining the fuel bowl on the transfer pump preliminary filter. Swing bail away and lower the bowl with element spring and gasket. The element may be replaced or flushed out with clean diesel fuel and reused. If damaged or coated with varnish or other non removable deposits, replace it. Clean bowl in clean diesel fuel and wipe clean with lint free cloth.
6. Install cleaned or new element with new gasket and spring. Slide bail into place and tighten bail locknut finger tight.
7. Fill the fuel tank and open fuel tank shut-off valve.

8. Operate the hand primer pump until preliminary filter bowl is filled with fuel.
9. Open bleed valve on the 1st stage filter. Operate hand primer pump. Close bleed valve when clear bubble free fuel appears.
10. Open bleed valve on the 2nd stage filter. Operate hand primer pump. Close bleed valve when clear bubble free fuel appears. After the 2nd stage filter is bled and bleed screw is closed, operate primer pump five additional times, to finalize bleeding the system of air. NOTE: Tighten hand primer pump handle securely be fore starting engine.

11. If the filters have been changed, fuel system has been bled and the engine still lacks power under full load, the fuel system pressure could be low because of damaged filters. Fuel system pressure can be checked by installing a 0 to 50 PSI gauge in the inlet fitting on the injection pump. The fuel system operating pressure should be 20 to 30 PSI. If it is above or below this, check the filters.