Clessie Cummins continued to innovate until his death. He identified the problem of vehicle brakes overheating and becoming non-functional during long, steep downhill descents. As a result, he designed and patented the first compression release engine brake. The design was first offered to Cummins, but Jacobs was ultimately the company with which he partnered. In 1954, the product was and still is sold under the Jake Brake name by Jacobs Vehicle Systems, Inc. As he approached eighty years of age, he designed, built, and ran in his basement shop a new concept engine.