How To Hook Up Vacuum on Demco SBS Stay-IN-Play for 2021 Jeep Wrangler Unlimited 4xe
Updated 01/24/2022 | Published 01/22/2022 >
Question:
Good evening, we are gathering the parts to set up our 2021 wrangler 4xe hybrid for flat towing behind our class c motorhome. We are looking at the demco stay n play brake system with wireless monitor. The install video refers to a splice into the vacuum line on the wrangler brakes. Our 4xe does not appear to have a traditional master cylinder with any vacuum lines coming out of it. Other 4xe owners have noted that the demco does not need the vacuum line to be hooked up to be operational. Is that correct? Or is there another system that would work better that does not have a vacuum line setup? I would prefer a hard wired system as opposed to one of the portable ones. Thanks!
asked by: Brandon H
Expert Reply:
The Demco SBS Stay-IN-Play DUO Supplemental Braking System part # SM99251 will work great on a 2021 Jeep Wrangler Unlimited 4xe. Since there is no vacuum assisted brake booster you'll simply plug the vacuum connection at the operating unit by removing and reversing the pre-installed check valve. Just take a pair of pliers and pull it out, then install the barbed valve in reverse order, simple.
Product Page this Question was Asked From
Demco Stay-IN-Play Duo Flat Tow Brake System for RVs w/ Hydraulic Brakes - Proportional
- Flat Tow Brake System
- Brake Systems
- Proportional System
- One-Time Setup
- Vehicle Battery
- Fixed System
- Power Assist Brake Compatible
- Hydraulic Brakes
- Indicator Lights
- Demco
more information >
Featured Help Information
Instructions
Continue Researching
- Shop: Vehicle Tow Bar Wiring
- Shop: Vehicle Tow Bar Brake System
- Shop: Roadmaster 4-Diode Universal Wiring Kit for Towed Vehicles - 7-Way to 6-Way Coiled Adapter Cord
- Shop: Safe-T-Plus Steering Stabilizer with Mounting Hardware Kit - Custom Fit
- Shop: Demco Stay-IN-Play Duo Flat Tow Brake System for RVs w/ Hydraulic Brakes - Proportional
- Search Results: base plate for tow bar
- Search Results: brake controller
- Search Results: 18294
- Search Results: nighthawk towbar
- Search Results: trim tool
- Search Results: stop light switch
- Search Results: flat tow
- Shop: Roadmaster Battery Charge Line Kit for Towed Vehicles
- Q&A: Is Demco Stay IN Play DUO Inline Air Pressure Regulator Needed For 2025 Ford Maverick Hybrid
- Shop: Blue Ox Patriot Portable Flat Tow Brake System - Proportional
- Q&A: Does ST28MR Safe-T-Plus Steering Stabilizer Fit Newer 2021+ Ford F53 Chassis With V8?
- Shop: Demco Stay IN Play DUO Inline Air Pressure Regulator
- Shop: Roadmaster Brake-Lite Relay Kit for Towed Vehicles
- Video: Roadmaster Direct-Connect Base Plate Kit DIY Installation - 2025 Ford Maverick
- Q&A: Does SMI Delta Force Portable Supplemental Braking System Apply Brakes Use Vehicle's Vaccum Assist
- Shop: Brake Controller
- Video: How to Install the Roadmaster 4-Diode Universal Wiring Kit - 2025 Ford Maverick
- Video: Demco Stay-IN-Play Duo Braking System Step-By-Step Installation - 2025 Ford Maverick
- Video: Curt Rambler Non-Binding Tow Bar Feature Breakdown
- Video: An In-Depth Look at the Roadmaster Battery Charge Line Kit for Towed Vehicles
- Video: Setting Up Your Roadmaster Towed Vehicles Battery Charge Line Kit - 2024 Ford Maverick
- Q&A: Why Isn't Roadmaster InvisiBrake Supplemental Braking System Good For Mountainous Areas
- Video: Review of CURT Tow Bar - Rambler Non Binding Tow Bar 7500 LBS - C25DQ
- Q&A: Best Flat Tow Setup For 2026 Ford Maverick XLT Hybrid
- Q&A: Recommended Flat Towing Set Up for a 2026 Ford Maverick Hybrid


