Best Supplemental Braking Systems Ranked

8 supplemental braking systems for flat towed cars.

Last updated: November 3, 2026

A supplemental braking system presses the towed car’s brake pedal when the motorhome slows, so the coach doesn’t have to stop both vehicles alone. Most states and provinces require one above a set towed weight. A breakaway system applies the car’s brakes if it ever comes loose, and a monitor in the motorhome shows when the brake is working. Portable units sit on the car’s floor and move between cars. Installed units stay hidden in one car and need no setup before each trip. Some work only with air brake motorhomes.

Prices were last checked November 3, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.

Full ranking 8

  1. Demco Stay-IN-Play Duo
    #1 of 84.3Full review

    For gas motorhomes towing one car. It brakes in step with the coach and stays out of sight.

    Amazon $1,165.57
    $1,165.57
    --Yes
  2. Roadmaster BrakeMaster 9160
    #2 of 84.3Full review

    For diesel pushers and other air brake motorhomes. It is the cheapest way here to get proportional braking.

    Amazon $960.78
    $960.78
    -3.8 lbYes
  3. Demco Air Force One
    #3 of 84.2Full review

    For diesel pushers towing one car. It is a well rounded installed brake for air brake coaches.

    Amazon $1,323.81
    $1,323.81
    --Yes
  4. Roadmaster Even Brake 9400
    #4 of 83.9Full review

    For owners who want proportional braking and may switch towed cars. It is the most expensive way to get there.

    Amazon $1,930
    $1,930
    --Yes
  5. Roadmaster InvisiBrake 8700
    #5 of 83.8Full review

    For owners who keep one towed car and want a brake they never handle. Proportional systems brake more smoothly.

    Amazon $1,380
    $1,380
    --No
  6. CURT RVibrake 4 52202
    #6 of 83.8Full review

    For owners who want a portable brake with a wireless monitor. Check that its braking style suits you before paying this much.

    Amazon $1,595.95
    $1,595.95
    ---
  7. CURT RVibrake Shadow 2 52201
    #7 of 83.7Full review

    For owners who keep one towed car and want a hidden brake with battery charging. Confirm the breakaway setup before buying.

    Amazon $1,595.95
    $1,595.95
    ---
  8. Blue Ox Patriot BRK2022
    #8 of 83.3Full review

    For owners who want a light portable brake they can control from the coach. The short warranty is a drawback.

    Amazon $1,410.45
    $1,410.45
    -6.2 lb-