raff, I have heard of an aerosol that you use to flush out the lines or I have taken a pump type oil can and used laquer thinner to flush and then blow out with plenty of compressed air. Main thing is to have everything CLEAN with no residue. When filling the trans, I usually fill about half of capacity when the convertor is empty. You don't want to overfill the case and blow oil out the vent. Also, better to underfill than to overfill when first getting it running. Put enough to indicate on stick when cold running and drive it ,heat up the trans and recheck it