Products Showing Parts for — {{ }}

No Results Showing Parts for — {{ }}
USD 1237.67
Part #: PBC44037

Pacbrake C44037 DirectMount PRXB Exhaust Brake

2004.5-2007 Dodge 5.9L Cummins (Manual) & 2006-2007 Dodge 5.9L Cummins (Automatic) w/ On-Board Air
Part #: PBC44037
Buy now, pay later using Affirm Logo during checkout.
Our Recommendations Compatible Products
Scroll to View More


Pacbrakes 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, Pacbrakes 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, Pacbrakes 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.

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.

As the engines 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

  • PRXB Delivers Strongest Braking Horsepower
  • Less Wear & Tear On Service Brakes
  • Ideal For In-City Driving Or Steep, Downhill Grades
  • Designed For Stock Turbocharger

Compressor not included, this kit is designed for vehicles that already have an on-board air system.
Shipping Restrictions Apply shipping restriction icon This product can not be shipped to these states: CA

Vehicle Applications

2004.5 Dodge 5.9L 24V Cummins
2005 Dodge 5.9L 24V Cummins
2006 Dodge 5.9L 24V Cummins
2007 Dodge 5.9L 24V Cummins


  • MFG. Number C44037
  • Manufacturer Name Pacbrake
  • Shipping Weight 35.00 lb.
  • Shipping Length 18 in.
  • Shipping Width 17 in.
  • Shipping Height 10 in.
  • Fuel Type Diesel
  • UPC 628480000985
  • Prop 65 Prop 65 WarningWARNING: Cancer & Reproductive Harm -
  • Internal L1.00R1.00


No Reviews Yet!

Write a Review

Include Your Order Number For a Chance to Win a $100 Gift card

Overall Rating

Your Information

Email Address will not be made public.

Questions and Answers

Is this everything needed??
View Staff Answer 

The Pacbrake C44037 DirectMount PRXB Exhaust Brake will include 1 - Exhaust brake housing 1 - Dash harness 1 - Dash switch and plate 1 - Nylon airline 12 ft 8 - Tie straps 1 - Solenoid valve 1 - Engine harness 1 - Sub group solenoid mounting fasteners 1 - 90° fitting 2 - Tee fittings 3 - Straight fittings 1 - Tire fill kit. The kit will require a compressor and a minimum of 100PSI to fully close the butterfly valve.

i have a 2006 dodge cummins with the he351cw turbo does this pacbrake fit
View Staff Answer 

The Pacbrake C44037 DirectMount PRXB Exhaust Brake is designed for use with the stock HE351cw Holset turbocharger that .

Ask a question about this product

Please allow up to 1 business day for reply.

More to Consider

Recently Viewed