When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
On mine it depends on the temperature, I like to keep at least 1/4 filled with fluid, but sometimes it drains itself completely out, and sometimes it is half-full, and I have no idea why, which doesn't help, but I have asked people this question before and they don't know why either