How Do You Bleed a Diesel Engine?

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To bleed a diesel fuel engine, check the fuel filters, access the fuel lines, open the cut-off valve, leak the fuel, and clean up everything. Bleeding a diesel fuel engine takes roughly 1 hour and requires mechanic tools, rags, a container for the fuel and an engine hoist.

  1. Check the fuel filters

    Locate the fuel filters, and examine them carefully for clogging. Look over the fuel line for holes, which cause air leaks.

  2. Find the fuel lines

    While some vehicles offer easy-access to the fuel lines, others are covered by a valve cover. If necessary, remove the valve cover to expose the fuel lines. Typically a wrench is needed to remove valve covers, though a screwdriver may also be necessary.

  3. Open the fuel cut-off valve

    The exact location of the fuel injector depends on the make of the car. However, typically the forward-most injector is the cut-off valve. Select the appropriate wrench to loosen the bolt, thereby opening the cut-off valve.

  4. Prepare the engine

    Place the engine in no-fuel mode. Attach an engine hoist to the engine to turn it over. Place the container on the floor near the engine to catch the fuel.

  5. Bleed the diesel fuel

    Using the engine hoist, turn the engine over. Diesel fuel should start leaking out from the cut-off valve. Watch for bubbles in the fuel leaking out of the valve. When there are no more bubbles in the fuel, tighten the bolt on the valve again with a wrench.

  6. Clean up everything

    Carefully move the engine back into its natural position. Dispose of the fuel in the container, and use rags to clean up any spills.