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Pacbrake PRXB High Performance Exhaust Brake - 2006-2007 6.6L GM Duramax Automatic Transmisson Without Option 2nd Alternator - C40070

Thoroughbred Sku #: PACC40070
Manufacturer Sku #: C40070

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$1,536.48 On Sale! $1,229.18



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Product Details

Product Name: Pacbrake PRXB Exhaust Brakes
Manufacturer: Pacbrake
Manufacturer Part #: C40070
Thoroughbred Diesel Part #: PACC40070
Fitment Notes: Pacbrake PRXB High Performance Exhaust Brake - 2006-2007 6.6L GM Duramax Automatic Transmisson Without Option 2nd Alternator - C40070

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. NOTE: All above kits are for vehicles with a factory exhaust system. For vehicles with an aftermarket 4 inch O.D. exhaust system you will need two adapters - PN# PAC C11342


  • 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 direct mount exhaust brake?

    Roger White | 5/21/2019

    DirectMount –This application is preferred because of the reduced number of connections between the exhaust brake and the turbocharger. The mating surfaces are both machined cast iron which eliminates any chance of exhaust leaks.

    For vehicles with straight back systems shortening of the header pipe is required to maintain an adequate amount of flex pipe. Vehicles with a 90° header pipe use a cast elbow to interface with the stock header pipe. Pacbrake offers replacement header pipes for some truck models.