Posting a YouTube link to Facebook is almost pointless these days. Facebook buries the post so that few people see it, because they don't want users leaving Facebook to go to another website. They do, however, promote Facebook videos heavily. But if you are trying to build a YouTube channel, it does you no good to post to both Facebook and YouTube.
I'm toying with the idea I've seen big channels do lately. Create your video and upload to YouTube as normal. Then create a 15-20 second "sizzle reel" of your new video, and include text in the video saying "To see the whole video, visit YouTube.com/mychannel." Then upload it to Facebook. That way your Facebook followers know you've released a new video, Facebook will heavily promote your post because it's native FB video, and you haven't given away the entire content of the video on a platform you cannot monetize (Facebook).