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Roadmaster BrakeMaster Air Line Assembly - Car to RV

Roadmaster BrakeMaster Air Line Assembly - Car to RV

Item # RM-921004-88
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Shipping Weight: 0.75 lbs
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Call 800-298-8924 to order Roadmaster accessories and parts part number RM-921004-88 or order online at etrailer.com. Free expert support on all Roadmaster products. Guaranteed Lowest Price and Fastest Shipping for Roadmaster BrakeMaster Air Line Assembly - Car to RV. Accessories and Parts reviews from real customers.
  • All Info
  • Reviews (14)
  • Q & A (9)
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  • Why etrailer?

Roadmaster Accessories and Parts - RM-921004-88

  • Tow Bar Braking Systems
  • Air Line Parts
  • Roadmaster
  • Assembly


  • Limited Lifetime Warranty


  • Air line assembly - vehicle to RV
  • Fits Roadmaster BrakeMaster braking system
  • Air line length: 88"

921004-88 Roadmaster BrakeMaster Air Line Assembly

Customer Reviews

Roadmaster BrakeMaster Air Line Assembly - Car to RV - RM-921004-88

Average Customer Rating:  5.0 out of 5 stars   (14 Customer Reviews)

- RM-921004-88

Product is good but the shipping could be faster 735144

- RM-921004-88

Product is exactly what I needed. 588725

- RM-921004-88

Julie is the BEST!!! Fabulous service, quick shipping and items received in great shape. I am going to use etrailer.com many time in the future. 554023

- RM-921004-88

Excellant customer service and quick re sponse. 524660

- RM-921004-88

good product, great service and fast shipping! I just hope the back ordered items come in soon. 511584

- RM-921004-88

Worked great! 486212

- RM-921004-88

I ordered some parts for my brakemaster tow package. The prices were very good and I received them in a timely manner. I will definitely use Etrailer again in the future. Thanks 411982

The products continue to work perfectly as designed
Jim M - 07/23/2018


- RM-921004-88

Exactly what we needed and delivered very quickly. 367682

- RM-921004-88

It works. 310266

- RM-921004-88

Got the help I needed ( as always!) confirmed that it was in stock. Recieved the day it was to come. Did I mention the staff, and how helpful they are? 288129

- RM-921004-88

I was on the road and needed the product fast. eTrailer came through with the correct product as quick as one could expect. 261819

- RM-921004-88

Quick shipping and in good condition. 239577

- RM-921004-88

Fast delivery. Exactly as advertised 193406

- RM-921004-88

Quality product from Roadmaster. Great service from Nikki @ etrailer.com 107395


Ask the Experts about this Roadmaster Accessories and Parts

  • Recommended Air Hose With Female Quick Connect
    It sounds like you are looking for the Roadmaster BrakeMaster Air Line Assembly - Car to RV # RM-921004-88, however you may just want the Replacement Female Quick Disconnect for SMI Air Force One Supplemental Braking System # SM99613. Another option is the Replacement Air Jumper for SMI Air Force One Supplemental Braking System # SM99666 which has a coiled tube for tension while allowing expansion up to 7 feet.
    view full answer...
  • Parts Needed to Install Brakemaster On RV When Tow Vehicle is Already Set Up
    For the BrakeMaster parts for the RV side of your setup you will need a car to RV air line assembly, # RM-921004-88. I also recommend the quick disconnect kit, RV side, # RM-921004-60. And you will need some air line, # RM450700, sold by the foot. Inside the RV you will need kit # RM-98850.
    view full answer...
  • Replacement Brakemaster 9000 Air Line Assembly RV to Vehicle
    The line that you need to connect the RV to the Towed Vehicle is part # RM-921004-88 from the BrakeMaster kit. You only need one of these. It has a male and female end. I recommend to use the RoadMaster BrakeMaster Second RV Kit part # RM-98200 that comes with the quick disconnect you need for the RV side and the airline. All the components you need for the vehicle side can be found in part # RM-98100.
    view full answer...
  • Air Brakes on New Hurbst Dump Trailer 20 Ton
    On your Hurst Dump Trailer, the order in which you hook up the hoses isn't an issue, but you do need to connect the correct hoses so you don't get fluid in your air lines. The air brakes will have an air hose that will allow your dump trailer brakes to operated correctly in line with your truck. The hydraulic system will be used to lift the trailer bed for dumping. This will be connected to a separate system. The only systems required to be connected for towing is your trailer brake...
    view full answer...
  • Correct Replacement Air Line Assembly for SMI Air Force One Supplemental Braking System
    The correct replacement is going to depend on the supplemental braking system you currently have. If you have the SMI Air Force One Supplemental Braking System # SM99243 then the Replacement Air Jumper # SM99666 that you referenced would be the correct choice. If you have the Roadmaster BrakeMaster # RM-9100 or # RM-9160 then the correct part is the Roadmaster BrakeMaster Air Line Assembly # RM-921004-88.
    view full answer...
  • Replacement BrakeMaster Parts, RV Side for Roadmaster BrakeMaster Supplemental Braking System
    For the BrakeMaster you will need a car to RV air line assembly, # RM-921004-88. I also recommend the quick disconnect kit, RV side, # RM-921004-60. And you will need some air line, # RM450700, sold by the foot. Inside the RV you will need kit # RM-98850. Dealing with air brake systems can be difficult but not impossible. I will email you a copy of the instructions for BrakeMaster # RM-9100. Current pricing is available on each of the product pages.
    view full answer...
  • Replacement Patch Cord for a Roadmaster BrakeMaster Supplemental Braking System
    We do have one, # RM-921004-88. This is the one that is listed in the manual as optional because it is longer but you can still use it in place of the original. Current pricing can be viewed by clicking on the link to the product.
    view full answer...
  • Replacement Parts Needed to Connect Brakemaster Supplemental Braking System to RV with Air Brakes
    In addition to the RoadMaster BrakeMaster Replacement Air Cylinder # RM-9100-50 to connect the RV's brakes to your Jeep Grand Cherokee all depends on what you already have. The Jeep will need the air lines and wiring installed in it, if it isn't already. If not you'll need # RM-98100. The kit to install into the RV, if it needs it, is # RM-98200. The air line to connect the two together is # RM-921004-88. Depending on how much of the pieces you need, and which system you have,...
    view full answer...
  • Replacement Rubber Cover for Air Brake System Fittings
    The Replacement Weather Cap with Wire for Roadmaster BrakeMaster Conversion Kit # RM450760-50 we have to protect the fittings when not in use. If I understand correctly it appears that is what you are seeking to keep road grime out. We do not have any other rubber boots or covers for that system. If you want the covers for the air lines, we have the Roadmaster BrakeMaster Air Line Assembly - Car to RV # RM-921004-88 which has the integrated covers but they are not available separately.
    view full answer...

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Info for this part was:

Updated by:
Isabelle B

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