GRC brake fluid

 The Gurley Oil company was started as a recycling company for waste oil. Based in Memphis Tennessee, the business expanded into the gas station business as the GOCO company in 1951. The company opened their own refinery and began to market their own products in the 1960s.
The main thrust of the business continued to be the recycling and disposal of waste oil and it was this activity that brought the company afoul of the growing anti pollution movement and the Army Corps of Engineers in 1969, as described in the book, An American Injustice, A true story of one man's 35 year battle against the EPA.  It's an interesting read, and is the subject of most of the online references to the Gurley oil company.

More here.

In the 1970s the GOCO gas station chain got a new name, Oil City USA and the Gurley oil business went from a sole proprietorship to a partnership of the owner, his wife and their son. The GRC (Gurley Refining Company) produced their own line of automotive fluids, the brake fluid can above being part of the lineup.