BRAKE GP-SERVICE 4V7334 - Caterpillar

Illustration 1 g02893220
(1) Fuel temperature sensor
(2) Fuel sampling port
(3) Fuel pressure sensor
(4) Secondary fuel filter baseNote: Do not use the fuel sampling port (2) for measuring the pressure.
Table 4
Troubleshooting Test Steps Values Results
2. Check the Fuel Pressure Sensor
A. Record the fuel pressure from Cat ET. Record the data in Table 5.
B. Remove the fuel pressure sensor (3).
C. Install an 8T-7860 Connector into the port of the pressure sensor (3).
D. Install the 110-6349 Fitting as onto the 8T-7860 Connector.
E. Install a 8T-0855 Pressure Gauge onto a 6V-3990 Coupler.
F. Install the 6V-3990 Coupler onto the 110-6349 Fitting as.
After the pressure sensor is removed, a code for low fuel pressure will become active. Reset all active codes and clear all logged codes by cycling the keyswitch to the Off position, after the sensor is reinstalled.
G. Record the fuel pressure on the pressure gauge. Record the data in Table 5.
Fuel pressure sensor
Result: The gauge value of the fuel pressure is within 137 kPa (20 psi) of the fuel pressure reading shown in Cat ET.
Proceed to Test Step 3.
Result: The gauge value of the fuel pressure is not within 137 kPa (20 psi) of the fuel pressure reading shown in Cat ET.
Repair: Replace the pressure sensor.
If the problem is not resolved, proceed to Test Step 3.
Table 5
Engine RPM Fuel pressure from Cat ET Fuel pressure from the mechanical gauge
800
1800
Illustration 2 g02893396
Fuel supply lines
Illustration 3 g02893278
Return fuel line
Table 6
Troubleshooting Test Steps Values Results
3. Inspect the Fuel Supply Lines
A. Visually inspect the following components:
- Fuel lines between the primary filter base and the inlet to the cylinder head
- Fuel cooler (if equipped)
- Fuel return line from the head to the fuel tank
- Fuel lines for restrictions, pinching, and swelling
Fuel Lines
Result: The fuel lines and the cooler are OK.
Proceed to Test Step 4.
Result: The fuel lines and the cooler are not OK.
Repair: Make the necessary repairs.
If the problem is not resolved, proceed to Test Step 4.
Illustration 4 g02893398
(5) Return fuel pressure regulator
Table 7
Troubleshooting Test Steps Values Results
4. Replace the Return Fuel Pressure Regulator
Fuel pressure regulator
Result: The regulator was replaced.
If the problem is not resolved, proceed to Test Step 5.
Illustration 5 g02893400
Typical fuel transfer pump
(6) Relief valve
Table 8
Troubleshooting Test Steps Values Results
5. Inspect the Relief Valve for the Fuel Transfer Pump
Note: The spring must move freely.
Relief valve
Result: The relief valve is stuck closed.
Repair: Replace the fuel transfer pump. Verify that the problem has been resolved.
Result: The relief valve is OK.
Repair: Clean the relief valve and reinstall the relief valve. Verify that the problem has been resolved.