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RoadMaster Brake Pressure Reducer for BrakeMaster Supplemental Braking System

RoadMaster Brake Pressure Reducer for BrakeMaster Supplemental Braking System

Item # RM-900002
Our Price: $135.31
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Accessories and Parts
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Shipping Weight: 1.47 lbs
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Roadmaster Air Line Parts Accessories and Parts - RM-900002
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Avoid overbraking with your BrakeMaster supplemental braking system by installing this brake-pressure reducer. Designed for vehicles with "active" or "continuous power assist" systems, such as Hummers and hybrids. 1-800-496-5010 to order Roadmaster accessories and parts part number RM-900002 or order online at Free expert support on all Roadmaster products. Great prices and Fastest Shipping for RoadMaster Brake Pressure Reducer for BrakeMaster Supplemental Braking System. Accessories and Parts reviews from real customers.
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  • Reviews (3)
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Roadmaster Accessories and Parts - RM-900002

  • Tow Bar Braking Systems
  • Air Line Parts
  • Pressure Reducer
  • Roadmaster

Avoid overbraking with your BrakeMaster supplemental braking system by installing this brake-pressure reducer. Designed for vehicles with "active" or "continuous power assist" systems, such as Hummers and hybrids.


  • Keeps your supplemental braking system from applying excessive pressure to your towed vehicle's brakes
  • Works with BrakeMaster and other supplemental braking systems that use pressurized air to brake the towed vehicle
  • Installs in vehicles with "active" or "continuous power assist" brakes
  • Connects to the air line and adjusts to set and lock the braking pressure
  • Includes mounting hardware and installation instructions
  • Limited Lifetime Warranty

Vehicles with active braking systems maintain braking ability even when the engine is off, resulting in a situation where minimal pressure is needed to engage the brakes. Supplemental braking systems that use proportional braking technology - causing the brakes in the towed vehicle to be applied with the same intensity as you use to depress them in the motor home - often end up inadvertently using too much force to engage your towed vehicle's brakes. This brake-pressure reducer allows you to set your system to use the exact desired pressure to avoid overbraking and the damage caused by it.

Some vehicles that have active or continuous power assist braking systems are the Hummer H3, Lexus GX 470, Ford Escape Hybrid, Mazda Tribute Hybrid and Mercury Mariner Hybrid. Consult your owner's manual or the vehicle manufacturer to determine whether or not your vehicle has this braking system.

900002 RoadMaster Brake Pressure Reducer for BrakeMaster

Installation Details RM-900002 Installation instructions

Customer Satisfaction Score:

Customer Reviews

RoadMaster Brake Pressure Reducer for BrakeMaster Supplemental Braking System - RM-900002

Average Customer Rating:  4.7 out of 5 stars   (3 Customer Reviews)

Avoid overbraking with your BrakeMaster supplemental braking system by installing this brake-pressure reducer. Designed for vehicles with "active" or "continuous power assist" systems, such as Hummers and hybrids.


Kevin and I have had Excellent experience with 99.9 percent of the people we worked with at etrailer. We did a DYI with a 2005 Itasca Horizon KD Motorhome and a 2012 Chevy Silverado 1500 4 x 4 in regards to flat tow installation. Have to say we are very happy with the helpful personnel at etrailer. Could not have done this without you all. We still have 1 part to install, hopefully this Sunday, brake pressure reducer. Let you know after that is installed. Thanks for all your help.


Product look strong. Got int in one we ek.



See what our Experts say about this Roadmaster Accessories and Parts

  • Does the Brake Pressure Reducer Install on the Vehicle or Supplemental Braking System
    Yes, the RoadMaster Brake Pressure Reducer, item # RM-900002, connects to the air line in the supplemental braking system and does not attach to the vehicle. The pressure reducer is designed to work with RoadMaster BrakeMaster supplemental braking systems, and does not work with the Even Brake Portable Proportional Braking System. The Even Brake system is not designed to be used with vehicles that have active (or, continuous power assist) braking systems.
    view full answer...
  • Brake Pressure Reducer Solution for Brakemaster Setup Where Tow Vehicle is Locking Up Brakes
    I spoke with my tech contact at Roadmaster and when I described your situation he said that the reducer part # RM-900002 would be the correct solution for you. He said that since you did pump the brakes to remove all of the vacuum in the vehicle brakes that the best solution would be the reducer so that you can fine tune the braking power of your setup.
    view full answer...
  • Is the RoadMaster Brake Pressure Reducer Needed for a 2016 Jeep Wrangler Unlimited
    The 2016 Jeep Wrangler Unlimited will not require the RoadMaster Brake Pressure Reducer part # RM-900002 when using the Roadmaster BrakeMaster System part # RM-9160. You will however need to use the RoadMaster BrakeMaster Custom Seat Adapter part # RM-88130 and the Roadmaster Brake-Lite Relay Kit part # RM-88400 if you are not using magnetic brake lights. I confirmed this with my contact at Roadmaster.
    view full answer...
  • Is Pressure Reducer Required when Using BrakeMaster Braking System on a 2018 Ram 3500
    The pressure reducer # RM-900002 is designed for use on vehicles that have active or continuous power assist braking systems so if that is what you have on your 2018 Ram 3500 then you will need the pressure reducer. But from what I could find the pressure reducer is not required on this vehicle. You will need a seat adapter though, # RM-88272. You will also need a stop light switch kit. If your truck has adjustable pedals use # RM-751461. If it does NOT have adjustable pedals use # RM-751460
    view full answer...
  • Replacement Parts for Roadmaster BrakeMaster 9000 Series Braking System
    If by pressure switch you mean just the break away switch for your Roadmaster BakeMaster 9000 then you can use part # RM-650898. For a complete BrakeAway Kit including the switch and air cylinder use part # RM-8600. If you refer to the Pressure Reducer we offer this as part # RM-900002. A page with many Roadmaster parts is linked for reference.
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  • Is Brake Pressure Reducer Needed When Using Roadmaster BrakeMaster on 2013 Ford C-Max Energi
    Yes, you will need to use the RoadMaster Brake Pressure Reducer # RM-900002 in order to utilize the Roadmaster BrakeMaster # RM-9060 with your 2013 Ford C-Max Energi. Please note that you also need the Custom Seat Adapter # RM-88295 and the Stop Light Switch Kit # RM-751459 to complete this installation. For a complete flat towing setup you will need a base plate kit, tow bar, safety cables, vehicle tow bar wiring, a supplemental braking system, and possibly a high-low adapter. If you...
    view full answer...
  • Is A Brake Pressure Reducer Needed On A 2017 GMC Canyon?
    No, the RoadMaster Brake Pressure Reducer for BrakeMaster Supplemental Braking System # RM-900002 is not needed for your 2017 GMC Canyon. The brake pressure reducer is needed for vehicles that have active, or continuous power assist systems that are present on Hummer's or Hybrid's. With the Roadmaster BrakeMaster # RM-9160, you will also need a Roadmaster Stop Light Switch Kit # RM-751472, and the Roadmaster BrakeMaster Custom Seat Adapter # RM-88315
    view full answer...
  • Does Reservoir of RoadMaster BrakeAway Kit for BrakeMaster Have Specific Mounting Location
    It is definitely a smart idea to use the BrakeAway Kit # RM-8600 with your Roadmaster BrakeMaster for RVs w/ Air or Air Over Hydraulic Brakes # RM-9100 although there is not necessarily a recommended spot we can offer to install the reservoir in a 2016 Ford C-Max. We have not had a chance to install this specific part in this specific vehicle, but I took a look at the owner's manual and since the air lines do need to be two feet away from a heat source like the engine, your best bet is...
    view full answer...

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Employee Michael H
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Employee Jameson C
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Employee Cole B
Installed by:
Cole B
Employee Wilson B
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Employee Isabelle B
Updated by:
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