ELBOW 4N6146 - Caterpillar

Table 1
Tools Needed    
Part Number     Part Name     QTY    
1U-5470     Engine Pressure Group     1    
3Y-2888     Connector     1    
3J-1907     O-Ring Seal     1    Note: The 5P-2720 Probe Adapter (Self-Sealing) and the 164-2192 Probe Adapter Gp may be used with the tools needed. These tools will be used in order to allow the installation of pressure probes in the future.
Illustration 1 g00294866
1U-5470 Engine Pressure Group The 1U-5470 Engine Pressure Group can be used in order to check the fuel pressure of the engine. The engine pressure group includes Special Instruction, SEHS8907, "Using the 1U-5470 Engine Pressure Group ". This instruction provides information about the usage of the group.Fuel Pressure Readings
Illustration 2 g00701422
Fuel Return Line (1) Cylinder head (2) Pressure regulating orifice (3) Tube assembly (fuel return) (4) Check valve assembly (5) Pressure relief valve (6) Fuel outlet port (7) Fuel galleryThe typical fuel pressure to fuel gallery (7) that is internal to cylinder head (1) can vary. At rated rpm and load condition, the fuel pressure to the fuel gallery should be 200 to 400 kPa (29 to 58 psi). At low idle, pressure regulating orifice (2) in tube assembly (3) maintains a minimum fuel pressure of 50 kPa (7.3 psi) to the injectors. Check valve (4) prevents fuel from leaving the cylinder head fuel gallery.Checking Fuel Pressure
Illustration 3 g00701423
(8) Fuel filter base (9) Fuel pressure tap (unfiltered side) (10) Fuel pressure tap (filtered side)To check the unfiltered fuel pressure, remove the plug from fuel pressure tap (9) from fuel filter base (8). Install the following tools to the fuel pressure tap: 3J-1907 O-Ring Seal, 3Y-2888 Connector and 1U-5470 Engine Pressure Group. Once the tools are installed, operate the engine in order to obtain the fuel pressure reading.To check the fuel pressure of the fuel gallery, remove the plug from fuel pressure tap (10). Install the following tools to the fuel pressure tap: 3J-1907 O-Ring Seal, 3Y-2888 Connector and 1U-5470 Engine Pressure Group. Once the tools are installed, operate the engine in order to obtain the fuel pressure reading.Note: Make sure that the fuel filter is clean before checking the fuel pressure. A fuel filter that is restricted will cause the fuel pressure at tap (10) to be lower than the fuel pressure at tap (9) .