BARREL 9T8448 - Caterpillar

Introduction
For Specifications with illustrations, make reference to Specifications For 3408C & 3412C Industrial Engines, RENR1312. If the Specifications in RENR1312 are not the same as in the Systems Operation, Testing & Adjusting, look at the printing date on the back cover of each book. Use the Specifications given in the book with the latest date.Troubleshooting
To troubleshoot engine problems make reference to Troubleshooting, 3408C & 3412C Industrial Engines, SENR6582.Fuel System
Either too much fuel or not enough fuel for combustion can be the cause of a problem in the fuel system. Many times work is done on the fuel system when the problem is really with some other part of the engine. The source of the problem is difficult to find, especially when smoke comes from the exhaust. Smoke that comes from the exhaust can be caused by a defective fuel injector, but it can also be caused by one or more of the reasons that follow:a. Not enough air for good combustion.b. An overload at high altitude.c. Oil leakage into combustion chamber.d. Not enough compression.e. Fuel injection timing incorrect.Fuel System Inspection
A problem with the components that send fuel to the engine can cause low fuel pressure. This can decrease engine performance.1. Check the fuel level in the fuel tank. Look at the cap for the fuel tank to make sure the vent is not filled with dirt.2. Check the fuel lines for fuel leakage. Be sure the fuel supply line does not have a restriction or a defective bend. Verify that the fuel return line has not collapsed in the sections subject to heat.3. Install a new fuel filter. Clean the primary fuel filter.4. To remove air from the fuel system, use the procedure that follows: a. Use the priming pump to remove air from the low pressure side of the fuel system.b. Loosen one-half turn the fuel injection line nuts at each adapter in the valve cover base. Move throttle lever to Low Idle position. Use the starting motor to turn the engine until fuel without air flows from the loose connections. Tighten the nuts. Because of the check assemblies in the injection pump outlets the priming pump will not give enough pressure to remove air from the fuel injection lines.5. Inspect the fuel bypass valve to see that there is no restriction to good operation.Fuel Transfer Pump
With the engine operating at full load speed, the fuel transfer pump receives fuel from the primary fuel filter. Fuel then moves through the ECM and the secondary fuel filters to the fuel injection pump.To check the fuel transfer pump pressure, disconnect the fuel line (from the filter) at the fuel injection pump housing inlet. Install a tee at the inlet and connect the fuel line to the tee. Connect a pressure indicator to the tee and start the engine. Fuel is delivered to the fuel pump housing at approximately 414 kPa (60 psi) at full load speed.If the fuel pressure is not up to specifications, stop the engine. Make a