TIP GP-ABRASION 6I6420 - Caterpillar

Illustration 2 g02469816
Location of the drain port in the outlet manifold at the high-pressure fuel pump (right side engine view)
(4) Plug
Remove plug (4) from the outlet manifold at the high-pressure fuel pump.
Start the engine and run the engine. Check each of the drain ports for fuel leakage. The drain port that is leaking will be an indication of the location of the leak in the high-pressure fuel system.
If leakage is present at the drain port on the right side of the engine, check the right fuel rail extensively for leaks.
If leakage is present at the drain port on the left side of the engine, check the left fuel rail extensively for leaks.
If fuel is found in the leak detection circuit, but not at the fuel rail plugs, inspect the condition of check valve (2).
If leakage is present at the drain port of the high-pressure fuel pump, check for a leak in the fuel supply line. The leak will be located between the fuel line connection at the pump and the fuel line connection at the right fuel rail.
If leakage is present at multiple locations, check the components that are associated with each location extensively for leaks.
Identify leakage at the left fuel rail or the right fuel rail:
Illustration 3 g02469957
(5) Plug Note: There is a plug at the fuel supply connection for each injector.
For the fuel rail that was identified in Test Step 4 as leaking, remove plug (3) from the fuel supply connections for each of the injectors.
Start the engine and run the engine.
Check the open drain ports at each cylinder for leakage. Record the results.
Leakage near assembled joints in the fuel line may be caused by a leak in the connecting joints for other fuel system components. Leakage at the seal joints for the fuel line connectors at the injectors is highly unlikely. Use the following information to identify other possible leak paths on the fuel rail:
Illustration 4 g02469977
Location of the pressure sensor for the high-pressure fuel system (left fuel rail)
(6) Fuel pressure sensor
If the drain ports on either side of the fuel pressure sensor (6) are leaking, the leak may be in a seal joint. Check the seal joint between the pressure sensor and the fuel rail for a problem.
Illustration 5 g02469983
Location of the crossover tube for the high-pressure fuel system (rear engine view)
(7) High-pressure fuel line that connects the fuel rails
If the leak coming from the drain ports near the crossover tube (7), there may be a problem in the connecting joints. Check for a problem in the joints between the crossover tube and the fuel rail.
Illustration 6 g02469984
Location of the fuel supply line for the high-pressure fuel system (right front side engine view)
(8) High-pressure fuel lines that supply fuel to the fuel rails
If the leak is coming from the drain ports near fuel supply tube assembly (8), there may be a problem in the connecting joints. The leak is probably in the joints between the tube assembly and the fuel rail. If these joints are OK, check the condition