A known problem with diesel engines is it's inherent lack of retarding power. Add a 6 - 8 percent grade, a large 5th wheel and the result can be overheated brakes, brake fade and a good chance of a run-away. The use of an exhaust brake and its retarding power means considerably less use of the vehicles service brakes. They not only wear less, they run cooler which means there is considerably less chance of brake fade and a run-away. Now your service brakes are there for you when you really need them.

For manual transmissions a shifter switch can easily be mounted to your existing shift lever, and used for activation and de-activation. An exhaust brake can also be used with an automatic transmission. Depending on your application, an external electronic controller is required to maintain torque converter lockup while the exhaust brake is engaged. Also an aftermarket valve body is a good idea to increase line pressure, to prevent lockup clutch slippage while the exhaust brake is engaged.

For '89 through '98 Cummins 12 valve engines, the use of 60# exhaust valve springs is required to get the maximum retarding horsepower. Peak retarding power is reduced by approximately 25% when 60# springs are not installed. Installation of an exhaust brake designed for later model 24 valve engines can damage a 12 valve engine, if 60# valve springs are not used.

Retarding power can be directly related to engine RPM's. The higher the RPM the higher the retarding power. The more times each piston travels through its cycle ( intake, compression, power, exhaust ) the more retarding power is generated. So downshifting can be required to achieve the appropriate amount of retarding. This graph shows the relationship of RPM to Retarding Horsepower for a standatd PacBrake on a Dodge Ram application. PacBrake's PRXB line of exhaust brakes automatically compensates for lower RPM's, so less downshifting is required.

For applications with aftermarket turbos where a turbo mount exhaust brake will not work, consider the use of a BD-Power or PacBrake Remote Mount exhaust brake. Remote mount exhaust brakes are available for both 4" and 5" exhaust systems.