Recommended Flat Towing Parts for a 2021 Ford F-150
Updated 11/17/2025 | Published 12/13/2024
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Question:
I’m getting confusing answers about the compatibility of the AF1 and my 2021 Powerboost Hybrid F150. Installer says I can’t use it because my truck doesn’t have vacuum assisted brakes brakes. I called Demco and they said simply cap the vacuum port on the unit and you’re good to go. It seems too simple to be true. Your thoughts? I was planning a Blue Ox tow bar and base plate, what else to I need?
asked by: Tony G
Expert Reply:
It is definitely that simple! There's a note in red in the vacuum connection section of the installation instructions on the Demco Stay-IN-Play DUO item # DM86VR that addresses your concerns. It states the following:
"If you have an electric brake assist and your vehicle requires the battery to be disconnected, leave the vacuum
line and check valve open to atmosphere. If you have electric brake assist and the battery remains connected,
remove the check valve, and turn it around or block off the vacuum check valve."
Here are the rest of the parts you will need to flat tow your 2021 Ford F-150:
Tow Bar and Safety Chains - Blue Ox Alpha 2 Non-Binding Tow Bar item # BX7380
Base Plate Kit - Blue Ox Base Plate Kit - Removable Arms item # BLU33FR
Wiring Harness - For LED Lights - Roadmaster Smart Diode 7-Wire to 6-Wire Wiring Kit for Variable Voltage LED Tail Lights item # RM38FR or for Incandescent Lights - Roadmaster Smart Diode 7-Wire to 6-Wire Wiring Kit for Variable Voltage Incandescent Tail Lights item # RM26FR
Charge Line - Roadmaster Battery Charge Line Kit for Towed Vehicles item # RM-156-25
High Low Adapter - The tow bar needs to be within 3" of level. If you measure the height of the inside top of the hitch receiver tube on your RV, and the height difference is more than 3 inches above/below the base plate tab height, you'll need a high/low adapter. I have linked a FAQ article that explains all this in more detail along with our selection of adapters.
Product Page this Question was Asked From
Demco Stay-IN-Play Duo Braking System for RVs w/ Hydraulic Brakes - Wireless Monitor - Proportional
- Flat Tow Brake System
- Brake Systems
- Proportional System
- One-Time Setup
- Vehicle Battery
- Fixed System
- Power Assist Brake Compatible
- Hydraulic Brakes
- Wireless Display
- Demco
more information >
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Jerred H.
11/17/2025
Hey, how did things go with the Demco Stay-IN-Play Duo on your Powerboost Hybrid F-150? Did capping or adjusting the vacuum line work as described in the instructions? Your update could make it easier for others with the same setup.