{"id":6473,"date":"2025-06-07T16:49:46","date_gmt":"2025-06-07T14:49:46","guid":{"rendered":"https:\/\/www.vaarzeker.nl\/?page_id=6473"},"modified":"2025-06-07T16:49:46","modified_gmt":"2025-06-07T14:49:46","slug":"diesel-engine-venting-roadmap-explanation","status":"publish","type":"page","link":"https:\/\/www.vaarzeker.nl\/en\/diesel-engine-venting-roadmap-explanation\/","title":{"rendered":"Diesel engine venting - Roadmap & Explanation."},"content":{"rendered":"

Brief summary - Diesel bleeding in 4 steps<\/strong><\/h3>\n
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  1. \n

    Is the problem solved? Does it need venting because of a dirty filter or empty tank? If so, resolve this first.<\/strong><\/p>\n<\/li>\n

  2. \n

    Bleed the fuel filter<\/strong><\/p>\n<\/li>\n

  3. \n

    Start the engine and check for leaks for problems<\/strong><\/p>\n<\/li>\n

  4. \n

    Bleed the atomizers (if necessary)<\/strong><\/p>\n<\/li>\n<\/ol>\n

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    Step-by-step instructions for beginners<\/strong><\/h2>\n

    Step 1: Is the problem solved?\u00a0<\/strong><\/h3>\n

    Why does the engine need to be bled? Is there a dirty diesel filter? If so, replace it first. Has the tank sailed empty? Then fill it sufficiently.<\/p>\n

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    Step 2: Vent the pre-filter<\/strong><\/h3>\n

    Most boat engines have two fuel filters, and two fuel pumps. We start by following the fuel line from the tank, working our way toward the engine.<\/p>\n

    Usually from the tank, the first thing you encounter is the pre-filter. That's a fuel filter that often has a sight glass under it. Is the fluid in the sight glass clean? Is it transparent and a little yellow? Then it's good. If it's cloudy, or completely colorless, it's not good. Shine a flashlight through the sight glass to get a good look at the contents.<\/p>\n

    \"\"
    Pre-filter with water separator<\/figcaption><\/figure>\n

    If the pre-filter is clean, or still empty, we follow the lines to the boost pump. This is usually a mechanical pump mounted on the engine block. In some cases, it is an electric pump suspended next to the engine.<\/p>\n

    \"\"
    Booster pump<\/figcaption><\/figure>\n

    On the booster pump there is a little lever or lever. When we pull it back and forth, we pump the diesel through. Before we do this, we first follow the line further up the engine, to the fine filter. On the fine filter you will find a small screw, usually 10, 12 or 13mm. This is the breather screw. Open this one turn.<\/p>\n

    \"\"
    Bleed screw<\/figcaption><\/figure>\n

    After opening the bleed screw, start pumping on the boost pump. The sight glass under the pre-filter should now fill with diesel. We keep pumping until a steady stream of diesel comes out of the screw. Then you can close the screw again.<\/p>\n

     <\/p>\n

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    Step 3: Start the engine and check for problems<\/strong><\/h3>\n

    Is the breather screw closed again? Then we will now start the engine to see if everything works again. Does the engine immediately start again? Then check that you don't see any more diesel leaking anywhere. Does the engine still not start? Then proceed to step 4.<\/p>\n

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    Step 4: Vent the atomizers (if necessary)<\/strong><\/h3>\n

    If the engine still won't start, there may be air in the fuel lines to the injectors, the high-pressure system.<\/p>\n

    \"\"
    Glands on atomizers<\/figcaption><\/figure>\n

    Here's how you do this:<\/strong><\/p>\n