• Ford Powerstroke
  • 94-97 7.3L
  • 99-03 7.3L
  • 03-07 6.0L
  • 2008 6.4L
• Dodge Cummins
  • 89-93 5.9L
  • 94-98 5.9L
  • 98.5-02 5.9L
  • 03-04 5.9L
  • 04.5-07 5.9L
  • 07.5-08 6.7L
• GM Duramax
  • 01-04 LB7
  • 04.5-05 LLY
  • 06-07 LLY/LBZ
  • 07.5-08 LMM

Pacbrake Exhaust Brake Mechanics

• << Go Back to our Pacbrake section

In order to have consistent and effective braking over the entire RPM range, it is important (and necessary) to maintain constant backpressure. To achieve this, Pacbrake’s patented design has incorporated an additional waste gate on the butterfly valve to regulate the amount of exhaust flow that is being passed through. The flow is controlled by a spring-loaded arm, whose pressure rating and location are key factors in the functionality of the PRXB. Located outside of the housing and away from the heat, the spring is able to maintain its strength and durability for years of proper and precise braking performance.



PUTTING IT ALL TOGETHER

CREATING & MAINTAINING BACKPRESSURE
Backpressure is created by exhaust flow entering the housing, hitting the closed butterfly valve and being forced back out in the direction it came. It is maintained by the pressure-controlled spring that is located on the outside of the exhaust brake housing.

PREMIUM BRAKING PERFORMANCE
As the engine’s RPM increase, the spring compresses and the arm moves away from the butterfly valve, therefore releasing more exhaust flow through the orifice. As the RPMs decrease, the spring releases and the arm applies pressure back onto the plate, covering the hole, and ultimately releasing a smaller amount of exhaust flow.

There is less than a 10% change in backpressure over the entire RPM range on the PRXB

PACBRAKE'S PRXB