What to Do w/ the Vacuum Line When Installing the Roadmaster InvisiBrake
Updated 01/19/2026 | Published 08/04/2024
Question:
I have a Demco Invibrake flat tow system part RM-8700 that I took out of my Jeep Wrangler and installed in my 2024 Ford Maverick. My question is: since the Maverick has electric brakes and does not need the vacuum line tapped into from the Demco Invibrake what do you do with the port on the back of the Demco Invibrake? Just plug it or leave it as is open?
asked by: Mark M
Expert Reply:
I took a look at the instructions for the Roadmaster InvisiBrake Flat Tow Brake System item # RM-8700. It states to "Leave the vacuum port as is and proceed to the next section"
I attached the installation instructions below. The section addressing the vacuum line is on page 11.
Product Page this Question was Asked From
Roadmaster InvisiBrake Flat Tow Brake System - Preset
- Flat Tow Brake System
- Brake Systems
- Pre-Set System
- One-Time Setup
- Vehicle Battery
- Fixed System
- Power Assist Brake Compatible
- Air Brakes
- Hydraulic Brakes
- Indicator Lights
- Roadmaster
more information >
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on Flat Tow Brake System
Jerred H.
1/19/2026
Hey, how did things go after leaving the vacuum port open on your InvisiBrake system in the Maverick? Did everything work as expected once you finished the setup? Your update could make it easier for others moving their system to a newer vehicle.