You mean that white cap thing that Joe used? Also, so while it's filling up should i just leave the cap undone, and once it is done cycling just cap it? but wont that just cause more air to get caught because I wont be able to cap the thing because of the little distance between the water and cap?
Should it look like this?
(CAP)
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RADIATOR(INLET)====== ------(T thingy)
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(PUMP)
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