The amount of oil your talking about is not near enough to fill this buffer! Sounds like there is a nasty glob of crap (that's a technical term for the stuff that comes out of buffers that have been full of water) blocking the fill. You can try compressing the buffer several time to try to blow it out or use a compressor but your best bet is to replace it. This is something you should be able to get paid x-tra to do if it wasn't in the specs.
