PIN AS 3150800 - Caterpillar

Contact with high pressure fuel may cause fluid penetration and burn hazards. High pressure fuel spray may cause a fire hazard. Failure to follow these inspection, maintenance and service instructions may cause personal injury or death.
Personal injury or death can result from improperly checking for a leak.Always use a board or cardboard when checking for a leak. Escaping air or fluid under pressure, even a pin-hole size leak, can penetrate body tissue causing serious injury, and possible death.If fluid is injected into your skin, it must be treated immediately by a doctor familiar with this type of injury.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting, and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Refer to Special Publication, NENG2500, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat® products.Dispose of all fluids according to local regulations and mandates.
Ensure that all adjustments and repairs that are performed on the fuel system are performed by authorized personnel. Ensure that these personnel have had the correct training.Before beginning any work on the fuel system, refer to Operation and Maintenance Manual, "General Hazard Information and High-Pressure Fuel Lines" for safety information.Refer to Systems Operation, "Cleanliness of Fuel System Components" for detailed information that is related to the standards of cleanliness that must be observed during all work on the fuel system.
Note: The fuel pressure in the fuel system must be below 1 MPa (145 psi) before the fuel system can be serviced. Refer to Systems Operation/Testing and Adjusting, "Fuel Rail Pressure - Release".Excessive bypass fuel flow by individual fuel injectors can affect engine starting, engine operation, and engine performance.Note: There are two different configurations for the injector bypass fuel line. One configuration routes the bypass line through a check valve to the fuel manifold on the back side of the high pressure fuel pump. This fuel then returns to the fuel tank. The second configuration connects to pressurised fuel on the inlet of the transfer pump.
Use the following procedure to check the fuel injectors for excessive bypass fuel flow:
Illustration 1 g06089454
(1) Fuel return line from the fuel injectors
(2) Fuel manifold
Illustration 2 g06089421
Alternate injector bypass fuel flow line of 20 cylinder engine
(3) Fuel return line from the fuel injectors
(4) Low-pressure fuel line
Illustration 3 g06089432
Alternate injector bypass fuel flow line of 16 cylinder engine
(5) Fuel return line from the fuel injectors
(6) Low-pressure fuel line
Disconnect the fuel injector fuel return line (1) from fuel manifold (2) at the high-pressure fuel pump or from the alternate line (3) or (5) on the low-pressure fuel system. Obtain a piece of plastic tubing that can be attached to the end of the return line. Connect one end of the tubing to the loose return line. Place the other end of the tube into a suitable container that can be used to measure the fuel discharge from the return line.
Plug the fitting