PacBrake PRXB Exhaust Brake - InLine Mount - 07.5-17 Dodge Cummins w/Aftermarket 4" Exhaust - C44038

Thoroughbred Sku #: PACC44038
Manufacturer Sku #: C44038

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Add a Mounting Group for your InLine Exhaust Brakes?

Product Details

Product Name: Pacbrake PRXB Exhaust Brakes
Manufacturer: Pacbrake
Manufacturer Part #: C44038
Thoroughbred Diesel Part #: PACC44038
Fitment Notes: PacBrake PRXB Exhaust Brake - InLine Mount - 07.5-16 Dodge Cummins w/Aftermarket 4" Exhaust - C44038

PRXB offers the highest braking power to lowest price ratio available. Pacbrake’s flagship product is the unquestioned leader in the supplemental brake industry. It has changed the way people think about exhaust brakes by providing performance, safety and durability that is unmatched by any other exhaust brake on the market.


  • The spring controlled pressure regulated mechanism on the exhaust brakes protects against engine overpressure
  • Pacbrake exhaust brakes are designed specifically for individual engine applications to maximize performance and reliability. They are not a one size fits all compromise
  • When the brake is deactivated, exhaust flow is unrestricted and won't interfere with power output Patented 90 degree Non-contacting Butterfly Valve is specially engineered to maximise backpressure while preventing seizing
  • The brakes use industry exclusive Arcor nitride coating on housing and components which increases resistance to wear and corrosion while strengthening the exhaust brake and adding lubricity
  • Precision machined surfaces on the exhaust brake eliminate the need for troublesome gaskets and risk of leakage
  • Maintenance is as simple as using the exhaust brake on a regular basis and periodically applying Superlube (Pacbrake's multi-purpose heat resistant lubricant which helps to prevent rust and corrosion)
  • Withstands extremely high exhaust temperatures
  • Compliant with latest emission regulations
  • Severe duty & military approved


  • Delivers the strongest braking horsepower, greatest speed reductions & shortest stopping distances possible without the use of service brakes
  • Maintains optimum retarding performance by maximizing the exhaust backpressure throughout the entire operating RPM range
  • Delivers maximum exhaust pressure (braking) as low as 1200 RPM through to the maximum allowable engine RPM
  • Provides increased performance and peace of mind with technology that protects the engine from the potential of overpressure

Kit Contents:

Every PRXB Automotive Kit comes with everything required for a complete installation. PRXB Exhaust Brake, Controller (when required for application) and AMP Onboard Air Kit, which includes: HP325 Series Compressor, 0.5 Gal Air Tank, 25ft Coiled Air Hose, Air Accessories and Fittings Kit.

Upgrade any standard exhaust brake to a PRXB for an improved design and a longer lasting brake with significantly increased performance. Tow & haul with complete control.


  • I have a 2007.5 dodge dodge ram 3500 with the 6.7 Cummins and an automatic trans. It has a factory exhaust break but im not happy with it. Can i install a pac brake in addition to the stock one for more braking power or is it a case of only being able to have one or the other installed and operational.

    Jesse | 10/11/2022


  • If I turn on my exhaust brake when my truck is first started, will it help to warm my engine sooner in cold weather?

    Jim Hader | 5/21/2019

    Yes! This is a bonus feature of an exhaust brake. It creates a restriction at idle that puts a slight load on the engine, causing the engine to warm up faster.

  • My exhaust brake comes on at a idle, why is that?

    Robbie Maines | 5/21/2019

    This is a normal operation if the engine is not warm. This allows the engine to warm up sooner by increasing engine load at idle. This feature can be turned off by cycling the toggle switch 8 times.

  • How can I tell how much back pressure my exhaust brake is producing?

    Wade Harris | 5/21/2019

    Every Pacbrake exhaust brake has a 1/8" NPT port tapped into the side of the exhaust brake housing. It has a port plug threaded into it from the factory. Remove the plug and install a back pressure gauge to this port. Go for a test drive and observe the backpressure readings.

  • What type of maintenance is needed on my exhaust brake?

    Adam Clark | 5/21/2019

    The exhaust brake requires very little maintenance. If it is switched off the brake will go through an "exercise cycle" which activates the brake 3x at startup. This is to ensure it does not stick or seize up with inactive use. Also, it is recommended to apply a few drops of Pacbrake Super Lube to all pivot points every 3-6 months.

  • Can I change the spring in my PRXB exhaust brake to a stronger one and will it make my exhaust brake harder?

    Jeremy Mineer | 5/21/2019

    No, you cannot. This spring is specifically calibrated and adjusted and made tamperproof on the assembly line. This is done to ensure each application is matched to the maximum engine backpressure and will not cause any damage. Tampering with the springs will void the warranty and potentially cause severe engine damage.

  • When should a turbo mount with a cast adapter be used?

    James Holder | 5/21/2019

    This application is the preferred option for vehicles with a tight 90° bent header pipe post turbocharger. The cast adapter is constructed from cast iron with machined mating surfaces on both ends, eliminating any chance of exhaust leaks.

  • What is a fixed orifice exhaust brake?

    Casey Rogers | 5/21/2019

    This is a traditional style exhaust brake tuned for maximum allowable backpressure at the maximum engine rated RPM by the drilling of a carefully selected hole size in the butterfly valve.

  • Explain an inlinemount exhaust brake?

    Tom Anderson | 5/21/2019

    InLineMount – Some vehicle configurations do not allow for clearance around the turbocharger, for installation of a DirectMount exhaust brake, these applications require an InLineMount. Inline exhaust brakes require a minimum 7" of straight exhaust pipe which is then cut out and exhaust flange adapters are installed in its place. Ensure the exhaust brake is mounted as close to the turbocharger as possible and away from road spray.

    NOTE: Clamped joints that exist between the brake and the engine must be welded to ensure that the joints cannot separate or leak under pressure. No flex pipe is allowed between the exhaust brake and the turbocharger.