Passing On Link Authority?

I've just been wondering about internal linking. I have a couple of pages on my site with follow links and if I internal link at least once per page, I'm sure a small amount of "link juice" will be transferred, but if there are A LOT of internal links (if I use an internal linking tool), then much more "link juice" will be transferred.

I have no idea if internal linking too much with EXTRACT the link juice from the page linking to the other pages.

Please let me know.

Thanks.