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PacBrake C40115 PRXB Exhaust Brake for Cummins C8.3L – 4" Inline Mount

PacBrake C40115 PRXB Exhaust Brake for Cummins C8.3L – 4" Inline Mount
PacBrake C40115 PRXB Exhaust Brake for Cummins C8.3L – 4" Inline Mount
PacBrake C40115 PRXB Exhaust Brake for Cummins C8.3L – 4" Inline Mount
PacBrake C40115 PRXB Exhaust Brake for Cummins C8.3L – 4" Inline Mount
PacBrake C40115 PRXB Exhaust Brake for Cummins C8.3L – 4" Inline Mount
PacBrake C40115 PRXB Exhaust Brake for Cummins C8.3L – 4" Inline Mount
PacBrake C40115 PRXB Exhaust Brake for Cummins C8.3L – 4" Inline Mount
PacBrake C40115 PRXB Exhaust Brake for Cummins C8.3L – 4" Inline Mount
PacBrake C40115 PRXB Exhaust Brake for Cummins C8.3L – 4" Inline Mount
: C40115
In Stock(10)
$995.00
$1,297.27

PacBrake Special


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Sale ends 03/31/2026 at 11:59:59
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PacBrake C40115 PRXB Pressure Regulated Exhaust Brake for Cummins C8.3L Inline Exhaust Applications


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, you can choose when to engage the exhaust brake with just the lift of your foot from the throttle pedal. 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.

Product Benefits:

  • Provides 50 percent More Braking Power at Lower RPM's. PRXB gives you the best hold-back in the 1400-1800 RPM range (where you typically drive).
  • The spring controlled pressure regulated mechanism on the exhaust brakes protects against engine over-pressure.
  • 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 maximize back-pressure 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.

Applications:

  • Motorhome and trucks with Cummins C8.3L - Inline Universal

Special Notes:

  • If adding exhaust brake to a vehicle that didn't previously have one, you will require Heavy Duty Valve Springs
  • Inline exhaust installation - Does not mount to back of turbo.

Other Information:

  • Delivers the strongest braking horsepower, greatest speed reductions, and 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
  • Withstands extremely high exhaust temperatures
  • Compliant with latest emission regulations
  • Severe duty and military approved
  • No risk of engine overpressure



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WARNING: Products may contain one or more chemicals known in the State of California to cause cancer and/or birth defects or other reproductive harm. For more information, visit www.P65Warnings.ca.gov

What components do I need for a 1996 F800 with a cummins 8.3 that does not currently have a pacbrake? I'm working up an estimate for my boss. Thank you for the help. ( Kirk Blythe, 07/15/2023 )
Not answered yet.
I have a 1995 Freightliner FL80 with a Cummings C8.3 engine that has no engine brake on it. I need to know what mounting group, control group and brake I will need.

Thank You
( Robert D Radcliffe, 01/21/2022 )

Our application guide shows that you would need PacBrake part #'s C40101 for the brake, C11546 for the mounting group and C10211 for the control group. You will also likely need to upgrade your exhaust springs to the heavy duty versions, part # 3916588KIT.

https://www.ultrarvproducts.com/C40101-Pacbrake-PRXB-Exhaust-Brake-C8.3-4-Full-Marmon-Cat-Flange

https://www.ultrarvproducts.com/C11546-Pacbrake-4-Mounting-Group

https://www.ultrarvproducts.com/C10211-Standard-Control-Group-Lighted-Toggle

https://www.ultrarvproducts.com/3916588-Heavy-Duty-Exhaust-Valve-Springs-For-C8.3l-(Genuine-Cummins)


Does this come with clamps and the associated components to allow the brake to be welded to the exhaust pipe?
Are any engine modifications required to see the most benefit from a brake?
( Joe Kobolt, 05/10/2019 )
This is the brake only. If you do not have an existing brake that you are replacing then you would need to order the correct mounting group (flanges and clamps) and a control group (electronics) for the brake to be fully installed. We would just need the vehicle details to let you know which mounting and control group your vehicle requires.

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