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General Information => Troubleshooting => Topic started by: ffgb on January 31, 2010, 03:03:10 pm
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Quick Question. I resealed my pump and put a new fuel filter on. When initially starting, I can see small air bubbles traveling through the clear fuel line from the fuel filter to the IP. After idling for about 3 seconds, the air bubbles disappear, just fuel is flowing. After I shut off the motor, I can see a air bubble starting to form at the top of the clear hose where it connects to the fuel filter. There are no air bubbles traveling from the IP back to the filter through the clear fuel line. If I apply upward force on the clear fuel line and create a high point, I can see more air bubbles coming out of the fuel filter. The air bubble is about a nickel/quarter in size if the fuel line is left alone, but If upward pressure is applied to the hose, there is air and no fuel from the high point of the hose to the fuel filter. My car starts up fine, there are no visible leaks anywhere on the IP, the fuel filter, the fuel lines, both the hard and soft lines, and the unions on the fuel lines themselves. I just want to know if this is normal. If not, what is the culprit?
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I'd guess the plastic hose isdried out at the fuel filter fitting, unless you reused crush washers.
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Brand new hose and brass fittings. I did reuse the copper washers at the filter side of the hose. Do you think it is sucking air? If so, then why does it stop sucking air 3 seconds into idling? Also, there is no leaking of fuel at that union.
Has anyone had this problem and how did you remedy it?
Thanks
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It should be OK.
You just started it and foam is sent back to the tank, then pulled back to the front.
It will take awhile of driving before all the air is out.
Shutting it off and giving it time to settle will help.
As air is pulled into the filter, it has a hard time getting through the diesel-soaked filter media.
It rises to the top, diesel goes around it and pulls through the filter.
As the filter gets clogged more air will be removed.
Removing a filter and finding it half full of air isn't surprising, especially if it's a clean filter.
So while the engine is off and the filter is sitting there,
some air will work it's way through the filter and out the top.
Especially since it was just started and some foam was getting pulled back into the filter.