Diesel tank vacuum

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Namakwalander

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No, I don't want to clean out the inside of the tank.

I have a problem that the tank makes a strong vacuum as the level drops. I seem to recall that when replacing the diesel filter previously, some diesel would run out from the pipe to the filter, but this past weekend it sucked air back into the tank and I could hear the tank expanding. Also does the same when one opens the tank cap.

Is there a separate tank breather that would suck air from atmosphere or is it the tank cap that is faulty?

Here is what the service manual says about the filler cap
20220522_174726.jpg
20220522_174826.jpg


There also seems to be a breather with filter on the tank, but the manual does not accurately describe this thing
20220522_175136.jpg
 
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