There is a wide variety of cooking oils from plant sources such as olive oil, palm oil, soybean oil, canola oil (rapeseed oil), corn oil, peanut oil and other vegetable oils, as well as animal-based oils like butter and lard.
We called a couple of the brake fluid companies and the answer was two to five years is a safe number for an unopened container. Wilwoodâs tech line claims that if the container is sealed, they feel it has an unlimited shelf life, but I would consider five years to be the limit.
A good rule of thumb is to have your brakes flushed about every 30,000 miles (48,280 kilometers) or so. Note that brake flushing and bleeding the brakes are two different procedures. Brake flushing involves removing all the brake fluid from the system and getting all-new, clean fluid inside. Brake bleeding just means removing enough brake fluid to get air bubbles out of the brake lines. So, make sure you get your brakes flushed regularly.