- Generator Set:
- C175-16 (S/N: WYB1-UP)
- E1127(1) Low Fuel Filter (suction side): Default set point −30 kPa (−4.4 psi)
- E1129(1) Fuel Filter (suction side): Default set point−45 kPa (−6.5 psi)
The fuel pressure on the low-pressure side of the fuel system is affected by the fuel supply pressure from the day tank. Also, the fuel pressure is affected by the restriction of the primary fuel filters. The pressures must not exceed the recommended values at any point in the system. Pressure sensors prompt the Electronic Control Module (ECM) to generate an alarm when the pressure exceeds the recommended values. An alarm is also generated if the primary fuel filters need to be replaced.
The default set points for the alarms are listed in Table 1. The pressures must remain in the required range if additional primary fuel filters are installed. Severe damage to the high-pressure fuel system will occur if the pressure requirements are not maintained.
| Event Code | Description | Default Set Point | Delay Time in Seconds |
| E1127 | Low pressure at the intake of the fuel filter (suction side) | −30 kPa (−4.4 psi) |
120 |
| E1128 | High pressure at the intake of the fuel filter (suction side) | 69 kPa (10 psi) |
30 |
| E1129 | Restriction at the fuel filter (suction side) | Fuel pressure at the inlet of the transfer pump −45 kPa (−6.5 psi) or Primary fuel filter differential pressure 103 kPa (15 psi) |
120 |
 | |
| Illustration 1 | g01812194 |
(1) Inlet to the transfer pump (2) Inlet to the fuel filter (3) Supply from tank (4) Return to tank | |
- The inlet pressure to the fuel transfer pump must maintain a minimum pressure of −45 kPa (−6.5 psi) at inlet (1) .
- The maximum allowed supply pressure at inlet (2) is 69 kPa (10 psi). Keep the supply pressure close to 60 kPa (8.7 psi) in order to maximize the life of the fuel filters. Supply pressures above 60 kPa (8.7 psi) but below 69 kPa (10 psi) are recommended. Supply pressures above 69 kPa (10 psi) will damage the lip seal in the transfer pump.
- The minimum allowed supply pressure at inlet (2) is −30 kPa (−4.4 psi).
- An auxiliary pump may be used to supply fuel to the engine at the required flow and pressure. The auxiliary pump must be a positive displacement pump. The pump must supply the engine with the required flow. The system must supply up to 41 L/min (10.8 US gpm). The system must also maintain the required inlet pressure. The pressure requirements are also available in Technical Marketing Information (TMI), located in the systems data.
Fuel quality and proper handling of the fuel system components is an essential part of the reliability and durability of the fuel system. Refer to the following publications for additional information:
- Reuse and Salvage Guidelines, SEBF9109, "Handling Procedures for the Components of the Common Rail Fuel System"
- Special Publication, SEBU6251, "Caterpillar Commercial Diesel Engine Fluids Recommendations"
- For additional information on fuel transfer systems, refer to Application and Installation Guidelines, LEBW4976.