I'm not sure what seal he means either.
Those holes are there to allow gasoline to escape if the diaphram ruptures or leaks on the upper portion of the unit.
The lower (vacuum) portion can suck oil & cause it to escape there too and is what usualy causes that. Apparently this was an 'exception to the rule'.
That's a Tiwang unit or a "mix-match" from some rebuilder; as the place where the bowel would be is blocked off with a 'newer type' cover plate also.
Mr. Kim; Were all glad your fixed.
