Dave, long-time professional driver, writing for Smart-Trucking.com has some advice for drivers uncertain of when and whether to use their Jake brake. The Jake brake, named for the Jacobs engine company that popularized it, is an engine mechanism that opens exhaust valves and released compressed air in the cylinders to slow vehicles without use of the service brakes. Due to its loud roar, some highways bear signs saying “No Jake!” but when used judiciously, it can be tremendously helpful (though the debate is ongoing about which conditions merit its use).
1. Do not use the Jake in icy or slippery road conditions! Avoid using it when the truck is not going at a controlled speed, also.
2. If you must use it, make sure your trailer is straight and lined up behind the cab to prevent jackknifing.
3. Using the Jake properly on mountainous or hilly roads can save wear and tear on the brake pads and tires. Dave recommends using a gear low enough to let the jake to do 90% of the braking when going down a steep grade.
4. Check engine temperature and oil levels before using the Jake—it should be running at operating temperature and no colder, and the oil levels should not be low. Test your brake at the beginning of your trip.
5. Operate the Jake in the shifting range, about 1100-1400 rpms, to protect the motor. Don’t use it when shifting; it may stall your truck.
6. “On a 3 position Jake, position 3 is strongest and used most often. Positions 1 & 2 are used in less than favorable road conditions.”
7. You can leave the Jake on at all times or turned on when necessary; if left on, it functions in a “no fuel position”—take your foot off the fuel to use it.
8. The noise of the Jake should be an incentive to only use it when safety is of utmost importance.
9. Follow the guidance of your CDL training instructor at all times, and keep these recommendations in mind!
