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Need to bleed air from diesel

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  • Need to bleed air from diesel

    I need to bleed the air out of the engines on by 3870. Can anyone give me the proper procedure for doing this? Do I crack the lines going to the injectors and pump until I see fuel coming out or do I crack the return lines on the top of the injectors?

  • #2
    If you have return lines, you should not need to bleed. Normally high pressure common rail motors have return lines and you never bleed those simply because the pressure will cut thru your hand

    You should only need to fill the fuel fllter with fluid
    1988 Cruisers Rogue 2420 -VP 290 DP now powered by custom 468 - http://forums.iboats.com/forum/owner...988-rogue-2420

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    • #3
      I need to bleed the air out of the engines on by 3870.
      Ayuh,..... Welcome Aboard,..... 3870, by whom,..??

      Is this a mechanical, or electronic injection diesel,..??


      • #4
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        The return line should be LP, but no need to touch these.
        If you have a manual priming pump on the engine, crack open the filter bleed screws just before mech pump then pump the priming pump by hand until fuel comes out with no bubbles or spuradic squirts. Then try firing her up.
        Failing this, crack open the injector compression fittings at each cylinder and with someone at the helm and someone else at the engine with spanner in hand...crank her over. She should fire up eventually, all be it roughly. Close and tighten (not too hard) each cylinder as a clear spurt of fuel is seen at each one.

        If you have pre filters (water separating), keep these closed when hand priming.
        It can all be a pain in the arse, but is usually caused by changing the filters incorrectly or running out of fuel.

        Note: if going as far as cracking open the injector compression fittings, do not loosen all the way. Only just enough so you can just move the fitting up and down by a mm or so. Leave plenty of threads on. These are HP and will do you damage....best case, atomised fuel in the face and eye...worst case missing finger and or hydraulic injection. Not good.