PRXB Exhaust Brakes

Diesel engines, unlike gasoline engines, don't slow down simply by taking your foot off the accelerator; they rely on service and supplemental brakes. An exhaust brake is a form of a supplemental brake, and they work much differently than their conventional counterparts.

Introducing the Pacbrake PRXB

Pacbrake’s flagship product, the PRXB (pressure regulated exhaust brake), is the unquestioned leader in the supplemental brake industry. The patented PRXB design delivers the strongest braking horsepower, greatest speed reductions and shortest stopping distances possible without the use of service brakes. It maintains optimum retarding performance by maximizing the exhaust backpressure throughout the entire RPM range. Unlike a typical exhaust brake, which requires high RPMs to work properly, the PRXB delivers constant exhaust pressure (braking) as early as 1200 RPM through to the maximum allowable RPM. 



Controlled by a master ON/OFF switch, Pacbrake’s exhaust brakes provide whisper quiet supplemental braking that allows service brakes to be used much less, ultimately saving you money. They have the ability to be left on all the time, making it ideal for in-city driving or for steep, downhill grades. This product pays for itself as less wear on the brake pads means fewer brake jobs. 

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.

PRXB Exhaust Brakes: PRXB To The Test

THE TEST
Two trucks, one equipped with a PRXB exhaust brake and the other with our competitors exhaust brake, are traveling down a 5% grade. Both vehicles start descending at the same time while traveling at a speed of 45 MPH. With a sharp corner ahead, both vehicles activate their exhaust brake...


RESULTS AFTER 60 SECONDS
The truck equipped with the PRXB slowed to a safe cornering speed (18 MPH) in just under 1/2 mile. In that same amount of time, the truck equipped with our competitors exhaust brake traveled 450 ft MORE and was still moving at a dangerous 30 MPH. Did this truck slow down in time?

*NOTE:  If you have upgraded to a larger turbo, or twin turbos, we offer a 5" in-line exhaust brake that is listed as an option in the drop down box below.

Automatic transmission kits (C44049/C44051) include built in transmission lockup controller.