I may be wrong but I have had detailed conversations with David Kirkham on this topic.you may also want to chat with morris on this site. But... You are using a catch can, when the
oil goes into the catch can it stays there until it gets drained. I am using a reservoir and all the kirkham cars as well. when the
oil goes in the reservoir it will drain back when you stop. see photo, also be careful not to add too much
oil to the diff.