Abstract: A leak diagnostic strategy for an engine equipped with a high pressure common rail fuel system includes a plurality of separate leak lines. Each of the leak lines is constructed and positioned to capture fuel leaking from one of several different high pressure spaces associated with the fuel system. Once a leak is detected, the location of the leak can be diagnosed by opening different leak diagnostic ports until fuel is evacuated from the system. Each of the leak diagnostic ports is associated with one of the leak lines. The system allows for quick determination of a leak location without cumbersome testing or partial dismantlement of engine related subsystems and components.

Abstract: High pressure fluid systems, such as those found in common rail fuel systems for engines, often need a low pressure containment system to appropriately address the possibility of fuel leakage around the engine. In addition, such high pressure systems also often require flow to go from one location, such as the common rail, to another location, such as a fuel injector, while undergoing a direction change because of spacial constraints around the engine. The present invention utilizes an elbow component with valve surfaces on its two faces that are oriented at about 90° with respect to one another. When the elbow component is fastened to the head with first fasteners and fastened to a flow limiter housing in another direction with second fasteners, a quill tube is compressed between the valve surface on the elbow component and a similar conical seat on a fuel injector in one direction while also compressing a short tube and flow limiter between the other valve surface of the elbow component and the common rail.