For any Cummins owner who has considered the jump to compound turbos, the thought of the installation can be intimidating. A detailed video from the channel Grumpy’s DIY, however, pulls back the curtain on the entire Cummins compound turbo kit installation, turning a complex job into a manageable, step-by-step process for any DIY builders out there.

Preparation and Teardown

The job kicks off by clearing a workspace, which means yanking the passenger-side tire and the wheelwell. From there, the mechanic pulls the stock airbox and charge pipe. The video points out crucial parts to save for later, like the original intake air temp sensor and a specific V-band clamp. After disconnecting the factory turbo’s oil lines and plugging the ports to keep dirt out, he unbolts the old turbo from the manifold and lifts it out of the truck.

Installing the New Hardware: Cummins Compound Turbo Kit

With a clean slate, the new, smaller turbo drops into the factory location. The narrator shows how to properly set the wastegate to the required 25 psi before it goes in. Down below, the exhaust pipe gets cut to make room for the new, larger downpipe. The video also tackles a specific hurdle for automatic trucks: swapping out the transmission dipstick tube, a task that requires careful work to avoid fluid spills and a leaky seal.

Mounting the Big Turbo

The centerpiece of this Cummins compound turbo kit installation, the large atmospheric turbo, needs a solid foundation. That comes from a heavy-duty steel bracket mounted directly to the engine block. To feed the turbo its required oil drain, the video demonstrates a clever trick: removing a factory freeze plug from the block to install a new drain fitting. With its support and oil line ready, the big turbo is set onto its pedestal.

Connecting the System and Final Checks

With both turbos mounted, the final stage is connecting all the piping. The mechanic positions the large downpipe and the hot pipe linking the two turbos, and the video walks through the proper tightening sequence to prevent leaks. He then routes the cold-side plumbing and installs the air filter. The last, most important step before putting the wheelwell back on is firing up the engine. This final check for any oil, boost, or exhaust leaks is the moment of truth that confirms the mechanic did the job right.