LML / LGH Duramax

Return Line Pressure Test Adapter

Fits 2011 - 2016

LML / LGH Duramax Diesels are equipped with Piezo injectors which require back pressure on the return side in order to function properly. In order to create this back pressure, the return line assembly is equipped with a return pressure regulator designed to maintain between 4 and 11 bar (58 - 160 PSI) in the system.

Failure of the return pressure regulator can create a hard-start or no-start scenario as well as a myriad of other difficult-to-diagnose driveability problems. In order to properly diagnose these systems it is necessary to take a pressure measurement on the return side. Unfortunately, the factory tooling that facilitates this is quite expensive, retailing around 250 dollars.

To use this pressure test adapter, simply disconnect an injector return line connector, and plug our test adapter into the fitting. The opposite end of the test adapter is equipped with a standard 1/4 in schrader valve which is the most common connection size for almost any fuel pressure test kit.

MADE IN THE USA

Replaces Kent Moore CH50375