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Demco Stay-IN-Play Duo Flat Tow Brake System for RVs w/ Hydraulic Brakes - Proportional

Demco Stay-IN-Play Duo Flat Tow Brake System for RVs w/ Hydraulic Brakes - Proportional

Item # SM99251
Our Price: $1,175.00
You Save: $493.98
Tow Bar Braking Systems

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Plug in and go: this permanent system gets you smooth, reliable braking with a one-and-done installation. Low-profile components designed to stay out of sight. Great Prices for the best tow bar braking systems from Demco. Demco Stay-IN-Play Duo Flat Tow Brake System for RVs w/ Hydraulic Brakes - Proportional part number SM99251 can be ordered online at or call 1-800-940-8924 for expert service.
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Demco Tow Bar Braking Systems - SM99251

  • Brake Systems
  • Hydraulic Brakes
  • Proportional System
  • Demco
  • Fixed System
  • Power Assist Brake Compatible
  • One Time Set-Up

Plug in and go: this permanent system gets you smooth, reliable braking with a one-and-done installation. Low-profile components designed to stay out of sight.


  • Guarantees smooth, reliable braking
    • Reads RV's brake light signal to ensure system only activates when you actually hit the brakes
    • Senses the rate of your RV's deceleration and triggers your towed car's brakes to slow down at the same rate
    • Lets you adjust braking sensitivity to suit your vehicle and your preference
  • Plug-and-play
    • System automatically turns on when your towed car is connected to the RV
    • Components install permanently and stay tucked out of sight
  • Monitors your towed car's braking with LED indicator on car's dash
    • Lights up when the brakes are applied
  • Avoids damage from over-braking by reactivating car's vacuum-assisted braking
  • Includes breakaway system and all necessary components
  • Made in the USA


  • Application: motorhomes with hydraulic brakes
  • Compatible with hybrids and other cars with continuous-power-assist brakes
  • Operating unit dimensions: 8" long x 5" wide x 2-1/4" tall
  • 5-Year warranty

stay n play duo review

"This is the top system I recommend if you have hydraulic brakes. Quality, reliable, tried-and-true. It just always works."

Do I Need a Braking System for Flat Towing?

A braking system is a must when towing a vehicle behind your motorhome. Without it, the weight of the towed car can create a safety hazard, strain your RV's brakes, and affect its warranty. Most states legally require a supplemental braking system, so if you don't use one and you end up in an accident (which is more likely since your RV takes longer to come to a full stop), your insurance and liability headache just doubled. You also won't have any breakaway system; if there's an accidental disconnect, there's nothing to bring your car to a stop.

Pros of a Permanent System

The Stay-IN-Play Duo is a permanent braking system, which means that it's a one-and-done. Once it's installed, there's no more setup that you have to do. When you plug in the power cord at the front of your vehicle, the system automatically turns on. Flip the on switch for the G-Force controller and just like that, you're ready to flat tow.

While the components are installed permanently in your RV and toad, they remain concealed and inconspicuous. None of them will interfere with normal driving, and most of the time they are invisible. And you don't have to find a place to store them between trips.

How Does the Demco Stay-IN-Play Duo Work?

The Stay-IN-Play Duo is unique in that it uses both an inertia sensor and your motorhome's brake light signal to activate. Having this double-check ensures that the system will only activate when it's truly needed.

Demco Stay n Play Duo operating unit

First, the Duo monitors your motorhome's brake light signal so that it knows when you're intentionally hitting the brakes. This ensures there's no false braking.

Second, the inertia sensor in the Duo senses the change in momentum of your toad (towed vehicle) as your setup slows down. It precisely measures this change so it can activate your toad's brakes to match the rate of the RV's deceleration; this is what makes it proportional. When you apply the brakes in your motorhome, the braking system will engage the brakes of the toad at the same time with the same amount of force. This keeps the RV and the toad in sync with each other, so whether it's a gradual slow down to a red light or a hard stop in an emergency, the toad and the RV will brake together.

Demco G Force Controller

It starts with the G-Force controller. The G-Force controller contains the inertia sensor that senses the change in your RV's momentum. You'll install it in the cab of your toad, underneath the dashboard. This keeps it out of the way but easy to reach so you can flip the toggle and adjust the knob.

Note: The G-Force controller must be pointed in the direction of travel - with the toggle switch facing the driver's seat - for the internal sensor to function properly.

The controller lets you adjust the sensitivity of the inertia sensor to determine how drastic the change in momentum must be for the system to trigger. Set the sensitivity low and the Duo will only engage when you forcibly step on your motorhome's brake pedal. Set it high and a mere tap on the brakes will get a reaction. It's totally up to you how sensitive you want it to be; a heavier vehicle will probably need more sensitivity, while a lighter one doesn't need to brake so hard. The knob on the face of the controller lets you easily program your setting.

Demco Stay n Play Duo operating unit

When the G-Force controller detects a change in inertia, it checks that there's a brake light signal from the RV to confirm that it is indeed braking. It then sends a signal to the main operating unit to activate; the main unit delivers pressurized air through an air line to the actuating cylinder that attaches to your toad's brake pedal. The cylinder will pull the pedal down, applying your brakes almost instantaneously.

Demco Stay n Play Duo cylinder mounted on the brake pedal

The actuating cylinder attaches permanently to the arm of your toad's brake pedal. Though it is permanent, it should not interfere with your everyday driving. In most vehicles, it is tucked up where you can't even see it.

Vacuum Pressure Creates Smooth Braking

When you're driving, your vehicle uses vacuum pressure to create the force needed to bring the car to a stop. On most vehicles, this vacuum-assist function does not work when the engine is off. As a result, a lot of supplemental braking systems have to use an excessive amount of pressure while braking the toad.

The Duo, on the other hand, reactivates the vacuum-assist function by tying into your car's vacuum line. Your car will brake evenly and naturally as it's being towed, so there's less risk of damage.

Built-In Safety Features

Demco braking monitor

Included with the Duo is an LED indicator light for safety and peace of mind. This LED, mounted in the toad (on the dash or on the back of the rearview mirror) and visible in your RV's backup camera, will light up whenever your toad is actively braking. It's a simple way to keep tabs on whether the system is working properly or if something is going wrong.

Most supplemental braking systems have a method of letting you know you when they activate, but not all of them are checking if the toad is actually braking. There could be an error that causes the system to activate without actually applying the toad's brakes. Or your brake pedal might actually be continuously depressed when it shouldn't be. But unless you have a system that's monitoring your vehicle, you won't know it until the damage is already done.

This braking monitor connects directly to your toad's brake light switch so it only lights up when the pedal is depressed and a signal is sent to the brake lights.

If there's a strong glare on your toad's windshield, the LED light strip might be hard to see. The wireless Coachlink system (SM99945 - sold separately) is a great solution to this problem; the monitor mounts right on your motorhome's dashboard so it's directly in view. This is a great add-on for convenience and peace of mind.

Demco break away switch

The Duo also comes with a breakaway switch, an absolute must for safe flat towing. If there's ever an emergency situation where your toad becomes detached from the motorhome, the breakaway switch will immediately activate the brakes and bring the vehicle to a stop.

This switch mounts to the front of your toad and wires into the Duo's operating unit. It includes a pin that connects to your RV's hitch receiver with a breakaway cable. If the toad and RV become disconnected, the cable will pull the pin out of the switch and trigger the braking system. A reserve air supply in the operating unit will then apply the brakes in the car.

What You Need to Flat Tow

Flat towing can be a much more convenient way to take your car RVing with you than using a trailer or a tow dolly. It'll save you storage space both at home and at the campsite, and it takes less time and hassle to hook up.

To flat tow your vehicle, there are 5 basic components you're going to need: a tow bar, a base plate kit, a safety cable set, tow bar wiring, and a flat tow braking system.

For the RV Between the RV and Towed Car For the Towed Car
Hitch Tow bar Base plate
Wiring plug Safety cables Braking system
Wiring adapter cord Wiring kit/diodes

The custom-fit base plate installs on the frame of your toad so you can connect the car to your RV with a tow bar. Hook up safety cables between the vehicles to ensure that the toad does not separate from the motorhome if the tow bar becomes detached. Tow bar wiring syncs your vehicle's signal lights with your motorhome's tail lights, as required by law in most states. Finally, the flat tow braking system - also required in most states - activates the brakes in the toad when you hit the brakes in the RV, making for smoother, safer braking, and preventing wear on your motorhome.

9599006 Demco SBS - (Formerly SMI) Stay and Play DUO Supplemental Braking System for Motorhomes with Hydraulic Brakes - Proportional

Replaces Demco SBS SM99251


Installation Details SM99251 Installation instructions

This Product Fits The Following Vehicles

Customer Satisfaction Score:

Customer Reviews

Demco Stay-IN-Play Duo Flat Tow Brake System for RVs w/ Hydraulic Brakes - Proportional - SM99251

Average Customer Rating:  4.8 out of 5 stars   (535 Customer Reviews)

Plug in and go: this permanent system gets you smooth, reliable braking with a one-and-done installation. Low-profile components designed to stay out of sight.

2017 Chevrolet Spark

I mounted this in a 2014 Chevy Spark. Finding a spot for the main control unit was interesting, but I found a video for a 2017 Spark that I could use. I did have to drill an extra hole in the mounting flange and car. I haven't taken it on a trip as of this time, but a tow around the block indicated it was working. One note, watch about placing the LED indicator behind the tinted part of the toad window. It makes it harder to see from the camper camera.

2020 Ram ProMaster 3500

Installing on 2020 Jeep Trailhawk :

Pic #0557 : Roadmaster Base Plate Kit , Demco Supplemental Braking System , Diode Wiring Kit , Demco Battery Charge Wire Kit

Pic # 0548 ,0551 , 0559 Had to adjust the bracket plate to line up with the upper bolt holes

Pic #6028 finished install , mounted the operating unit to the top fuse box cover using automotive Velcro . Air cylinder , controller and LED light installed . Aside from the base plate bracket not lining up with the upper bolt holes I would give it 4 stars . My son in law is a master at solving mechanical issues .


The Demco stay-n-play braking system has worked flawlessly for a full season of towing! The one time installation went smoothly and all components fit and functioned perfectly.
Very easy to use, connect to tow vehicle, flip a switch, and it's ready to tow. Disconnect from tow vehicle, flip a switch, it's ready for normal driving.
Would highly recommend this setup over other braking systems.

2020 Jeep Wrangler

Absolutely great product and worth the time and effort to install. Once installed and "adjusted correctly" this unit is flawless. I installed it with everything else from ETrailer in 3 days, taking my time and I have a very clean installation. Once installed the tech support guided my "sensitivity" level for the perfect application. Also their TECH support was on it both times I called. The other was in ref to a brake light switch sold by etrailer but was not needed for this and they provided the intel off the top of his head. Absolutely recommend this product and both DUO and Etrailer as companies.


Works great! I would buy it again. Tow a 2021 Jeep Wrangler, 5400 lb., And glad to have the braking help, especially in the mountains. Low maintenance, no complicated wiring between motorhome and Jeep.



Still working great. Simple to use and effective. I have recommended it to many fellow RVers.

2005 Jeep Liberty

I'm very pleased with this Stay-in-Play /DUO Braking System which I installed on my 2005 Jeep Liberty. I debated wheather I dared install it myself, but with the video instructions I decided that I could. I watched the video a couple of times, then followed it step by step during the installation, and it went pretty smoothly. One issue I had is that they changed the instalation of the LED indecator light, since the making of the video, so the parts did not come as described on the video. I do prefer the new method, as described in the installation manual, but it does require a toggle switch to turn it off. I installed one just below the Control Unit inside the car (see photo). I was also very impressed since, right after ordering the system, I found it for less on another web site. I emailed eTrailer about my disappointing discovery, and they credited me back the difference. GREAT COMPANY!

Robert P.


One year later, the system is still working great. Still very pleased.

2016 Ford Edge

Thanks to installation videos provided by etrailer, I felt confident that I could do the install myself. I had never pulled off moldings and panels in a car before, but with your videos as guidance , it was a breeze. This system was going into a 2016 Ford Edge 3.5L AWD and your (and SMI's) instructions call for installation of 2 check valves. After calling SMI to clarify the install points, it got even easier, as only one valve is required, and is ridiculously simple to install it. No cutting of original car hoses required (see photo). After everything was installed, the whole setup just simply worked, no troubleshooting required. That was fun and it is totally doable, even for the average guy like myself.

Herbert M.


The rear-view camera display in my RV is not good enough to show the operation of the brake notification LED which is applied to the rear-view mirror in the towed car. I installed a small light in the RV dash and ran wiring all the way back to the toad, with a disconnect plug at the hitch, of course. Now it is easy to see when the car brakes come on. Else, the system works great.

2014 Honda CR-V

After watching the excellent installation video I had very little trouble installing this product. I like the fact that it is a stay-in-play system that literally requires only the flip of a switch to activate. The major components are all installed out of the way, yet are still easily accessible. As for the braking system itself, I find it operationally excellent and believe this product choice was a great one.


I am very deceived and feel I have bee fooled by the false affirmation, this is not proportional. I DO NOT RECOMEND THIS PRODUCT.
This system is nothing but proportional. All proportional wording or video is misleading should be removed. It's actually an on-off system. When braking light is on and the tilt sensor actually (on-off) is on the pump is on at full pressure pressing the brake until it bottoms out, period. The pump inlet creates a vacuum for the brake booster and the pump outlet is for the cylinder pressing the brake. All triggered by a simple switch. Nothing is regulated or proportionally controlled. Totally false information is provided here. Unfortunately the initial concept is good, but lacking the extra electronic pressure regulator and electronic control.
I had to set the angle switch so the system ONLY TURNS ON in the event of an emergency, otherwise it will brake fully and destroy your towed vehicle brake.
I am sure this review will not appear and will be deleted by the moderator. Too many good fake reviews...

Etrailer Expert

Brooke M.


I reached out to the manufacturer about this and they said what makes it proportional is the system works on two signals, the first signal needed is the brake signal that comes electrically from the coach, the second signal is when the towed vehicle feels forward inertia. The pump does not come on full, it slowly ramps up pressure, the more inertia felt the longer the system runs, the longer the system runs the more pressure that the system creates. The more pressure the system creates the harder the brake pedal is depressed. I also asked about the sensitivity issues you seem to be having and Demco said they have heard of that before when the sensor isn't installed level, as outlined on page nine of the instructions.


Haven't actually had the chance to tow behind yet so this is just for the install. It took me quite a long time to install but, that's not the products fault. Everything you need to do the job is included.
I only give it 4 stars because the system uses the towed vehicles battery to activate the vacuum/compressor pump, so it would be possible to run the battery down as there is no charge circuit from the towing vehicle. I did choose to add one though. Other than that I'm sure it'll work fine. It was installed on a 1983 Vanagon.



Im not in the car when it works, but the indicator light comes on so I assume they work. Honestly, my motorhome is so big I cant tell if there working or not, mostly I stalled to be legal and safe. I like it.

2019 Jeep Wrangler

great kit for installing a supplemental braking system in my 2019 jeep wrangler. It takes several hours to install, but if you follow the instructions and watch the video, it's a pretty straight forward install. Just think it through and plan where you'll route the wiring and hoses. The hardest part was being flexable enough to mount the hardware to the firewall behind the brake pedal, but that's not a fault of the system.

2013 Jeep Wrangler Unlimited

Just towed for the first time using this system. Worked great on our Jeep. Now we just flip the toggle switch to turn on and off. Install was a bit of a challenge, but the Demco help line was very helpful.

2003 Subaru Outback Wagon

I chose to go with this unit because I didn't like the idea of the other types that mash the brake pedal without any vacuum assist & the fact that you have to remove, then reinstall them each time you want to use the car.
This ended up TOUGH install. Not because of the unit, but rather the lack of ANY room under the hood on my 2003 Subaru Outback Wagon to mount the operating unit. The only place I could find that would be out of the way was under the driver's seat of all places! Luckily there was JUST enough hose with the unit to reach all the way to the brake booster. I had to cut the carpeting so the seat would clear the operating unit during movement without any chance of contact. There was no hole in the firewall large enough to accommodate the hose so I had to drill a hole for that although I was able to route the wiring through a small rubber grommet. Routing the hose to the firewall was a real challenge! I ended up running it through the heater duct under the driver's floor mat to the left side kick panel, then up over the pedals keeping clear of any moving parts. WHEW!!
The brake pedal actuator went on without much fuss, although with my large feet I have noticed I'll catch the actuator with my toe on occasion. I may mark the location it's in now & merely raise it up a tab in between trips.
The wiring was pretty much straight forward, there was plenty of included wire & I had JUST enough room tho mount the G-Force Controller on the left kick panel covering without interfering with my feet.
The breakaway switch I fastened to the body in front & below the radiator.
I read where everyone was saying you need to have a battery cut-off device to keep the braking system from draining the battery over time, but I had power from the RV keeping the battery fresh so I didn't worry about that & saved myself the $180 for the cost of an automatic battery disconnect.
After installation, I sat in the car while we towed it around the neighborhood to see how it worked & made the necessary adjustments to the G-Force Controller. Now THAT was weird! What with the car steering itself & braking too.
We just got back from a 4,000+ mile trip & everything worked fine. On occasion I forgot to flip the switch to turn the system off, but it didn't seem to make much of a difference.
All in all a great system!


Erica G at etrailer was very helpful with managing my order and getting it to me w/ regular updates. The installation takes a lot longer than all of the etrailer 30 min videos but after it’s installed it’s easy to activate.


It wasn't easy to get everything installed in a way that looked neat and professional but in the end the ease with which you can hook up the car and start towing makes it worth it. I bought a replacement factory vacuum pump line so that I didn't have to worry about ruining the original one and as a result the installation looks that much better. Literally all I have to do is flip a switch once the car is connected and I'm ready to go. Given a second opportunity to do the installation I would mount the LED light strip vertically on the backside of the rear view mirror to make it a bit more visible but other than that, I'm happy with how it turned out and the system works great.


I personally installed this on my 2020 Jeep Wrangler and have towed it using this braking system over 4K miles and have had zero issues. Would definitely recommend! The installation instructions were well written and included an easy to read wiring diagram making is easy to install and the very knowledgeable etrailer support was a bonus too!

2018 Jeep Wrangler

After doing much research and reading many reviews and watching a lot of your instructional videos I chose the Stay-in-Play Duo. It came complete with instructions and extra parts for any application. I like the fact that after everything is installed it is just a matter of flipping a switch and checking it out and drive off. I mounted it in a 2018 Jeep wrangler, not very much room for the operating unit, but I I went off of one of your videos on a 2017 Jeep Wrangler Unlimited and mounted it underneath above the cross frame below and behind the radiator but still protected from the elements. Not a lot of room under the dash either, but everything is in and looks great and ready for the 1st trip.

2012 Dodge Charger

I installed this in a 2012 mini Cooper S. With the turbo charger there is no room in the engine compartment for the system unit, so I mounted it under the passenger seat. I had to remove the seat, cut out the carpet, mount the unit, and then buy longer seat attachment bolts. I used half inch thick spacers between the seat track in the floorboard. Made a long run for the vacuum hose to get up to the engine compartment through the firewall. By removing the cowling on the driver side, it exposes a huge Gromit where the main wiring harness passes through the firewall. It actually had two nipples ready to be cut off to run the vacuum hose and the wires through — so that part was pretty easy.
I haven’t towed it behind the motorhome yet, but it passed all the start up tests the first time!


Great product. Been towing my Jeep behind our Wanderloge using this set up for a year. Easy to install and works as expected. Keep in mind - these work on the brake light signal from the towing vehicle so if your tow vehicle is wired to flash your brake lights along with your turn signals when you turn on the hazard flashers, it will apply the brakes on the towed vehicle in sync with the hazard lights on the towing vehicle. So we learned not to use the hazard lights on the Bus when hooked up. If we are in steep mountains that slow us down, we just turn on the hazards in the Jeep and leave them on.


Very happy with the way this turned out. Video was very helpful. Only thing I didn't really care for was the red LED that was to be mounted on mirror. Purchased a red LED light at parts store and mounted in grill, see picture, using alternate connection. Much easier to connect and much easier to see in RV camera.

2015 Jeep Wrangler

SMI Stay in Play Duo installation in 2015 Jeep Wrangler Unlimited –
Packaging was great with everything needed included plus extra items for various installation methods of you’re choosing. Upon initial investigation and survey, everything except the CD Information pack was accounted for.
No big deal, as I had previously watched 2 different Youtube installations found on the internet. In fact, the internet videos were what I used as my step by step installation process, and the written instructions were only used for concerns where the video may not have been as clear as I had hoped for.
Understanding that everyone has their own style and methods for doing this project, I purposely was not in a hurry to rush through it. All in all, I took @ 8 hours to install the Adapter 4 to 6 pole #30637, the EZMount Tow lights Kit, and the Stay in Play Duo Braking System.
I choose the EZMount because I didn’t want to mess around with the OEM taillights and wiring. Magnetic lights don’t work so well on composite tops and I didn’t want to stick them to the sides of te Jeep, so I modified the EZ mount to wrap around the thickness of the rear glass hatch on both sides. I added a 2”x 4” pc of Velcro on the inside of the glass hatch and the mating surface of the plastic light housing - to hold the lamps in place until the rear gate was closed.
I ran the wire harness on the inside under the trim all the way up to the front and through the grommet in the firewall. The flat 4 wire was routed and secured up to the Adapter 4 pole to 6 pole that I had fastened to the Blue Ox base plate.
The actual installation of the SMI unit and assorted parts went rather smoothly. Most difficult issue was the lack of working space in front of the driver’s seat area. Installing the screw that holds the G force controller on the front (the side towards the front of the car) was difficult as it was almost a blind installation due to lack of room. The nut and fender washer used through the fire wall for attaching the air cylinder cable bracket was a challenge to reach - tight fit with not much room for one's hand and arm.
Other than that, no big surprises – just a lot of tedious steps to do when you want to be sure that it is being installed properly – take your time and don’t be in a hurry.
Once everything was installed – it all worked when I checked the system out. The only thing that may seem a bit odd is that when setting the G force initially, the compressor will shut off while adjusting per instructions. To do this initial adjustment, the wife stepped on the brake in the Motorhome, with the switch “On”. The compressor starts, and the brake is pushed down by the Air Cylinder, at which time I slowly adjusted the G force until the compressor shuts off. I secured the adjusting bolt and I told the wife to take her foot off the brake and then re-apply them. The compressor did not start again and the air cylinder did not apply the brakes in the Jeep. After setting the G force per instructions, the unit didn't turn on when the brakes in the Motorhome were applied - but since we were not moving - all I can assume is that the brake system will function while slowing down once the accelerometer setting (the sensitivity setting on the G force box) has been met. I assume that the sensitivity setting method includes a way to ensure the Jeep brakes are not engaged too frequently and only until needed.
This is the only step that is a tad bit confusing without an explanation as to what to expect once the G force sensitivity is set.
Lastly, I checked the brake away switch and it turned the compressor on and applied the brakes as expected.
Overall - the installation went rather smoothly. Can't wait to see how the product works once we hit the road. I'll check back and provide an update later.

Mike A.


Still working as expected, trouble free and no problems since the install.


I selected this item as an alternative to braking systems that sit in front of the driver seat and must be put in and taken out each time it is used. I like the fact that it is nearly undetectable once installed and works seamlessly. On installation the most difficult part was drilling the holes to screw the unit under the driver seat. The carpet being the primary problem in my experience, as it bound up around the drill bit.


This braking system works great, much better and easier than other RV tow-ers that I run into from campground to campground. And although the install is not simple, the video instructions by Etrailer made everything go together without a "hitch"!

2019 Jeep Grand Cherokee

had to make a bracket for under driver seat because the e brake would not allow the g-force controller to be place on the side panel.
the wires had to be extended to reach up to the controller in the engine compartment. Used a piece of aluminum plate to make a bracket mounted on strut frame that can easily be moved for other maintenance


Installation does take alot of additional kits due requirement of Jeep to disconnect battery. Very pleased with system. Wiring print was a real plus and online video

Show More Reviews

See what our Experts say about this Demco Tow Bar Braking Systems

  • Is The Demco SBS Stay-In-Play Braking System Compatible With A 2022 Jeep Wrangler Sahara Altitude
    We just haven't had one in yet to test fit it ourselves, but I called Demco and spoke with their tech who stated that the Demco SBS Stay-IN-Play DUO Supplemental Braking System # SM99251 is a compatible fit for your 2022 Jeep Wrangler Sahara Altitude. If you need some recommendations on base plates and wiring then let me know what tow bar you have since I'm assuming you would like to just reuse the tow bar you've already been using.
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  • SMI DUO or Invisibrake Recommendation for 2005 Jeep Wrangler
    The SMI DUO # SM99251 is the best option for supplemental braking for a vehicle that permanently installs. Our installers prefer this kit to all of the other ones as it's got an easier install and performs really well when flat towing. For your 2005 Jeep Wrangler this would be the best option. I attached an install video for this on a similar Wrangler as yours for you to check out too.
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  • Engine Light On and Cruise Control Doesnt Work After SMI Stay-IN-Play Install on a Jeep Cherokee
    I spoke to my contact at Demco about the issue you are having with the SMI Stay-IN-Play DUO Supplemental Braking System part # SM99251 on your 2015 Jeep Cherokee. They stated that this could be caused by either splicing into the wrong stop light switch wire or a check valve has been installed backwards. If you had a shop install the unit then I would take it back to them immediately otherwise you can follow the steps below. If you take a look at page 8 in the instruction manual for the...
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  • Recommended Installation Location for Operating Unit on SMI Stay-IN-Play DUO for 2016 Kia Soul
    The operating unit for the SMI Stay-IN-Play DUO Supplemental Braking System # SM99251 referenced in your question can be installed in the engine compartment but should be away from any extreme heat source. Also keep in mind that the connections will need to be easily accessible. A good location on your Kia Soul might be behind the grill, as long as it doesn't restrict air flow to the radiator. I have attached the complete installation instructions on this excellent proportional braking...
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  • Is The Demco Stay-IN-Play DUO Compatible With A 2021 Jeep Cherokee
    According to our installer expert team, we have no reported trouble of installing the Demco Stay-IN-Play DUO # SM99251 on a 2021 Jeep Cherokee and is confirmed to fit. I've linked a video of one of our installers installing the Decmo Stay-IN-Play on a 2020 Jeep Cherokee.
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  • Is SMI Tow Bar Braking System # SM99251 Compatible w/ Electrical System on 2014 Jeep Wrangler Sahara
    Yes, the SMI Stay-IN-Play DUO Supplemental Braking System, # SM99251, is compatible with the electrical and vacuum systems on the 2014 Jeep Wrangler Sahara. I spoke with my contact at SMI to confirm this.
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  • Supplemental Braking System Recommendation for Flat Towing Vehicle w LED Indicator in Tow Vehicle
    That light was part of the supplemental braking system that was installed on the HHR and tow vehicle. For a system that we like better than the Inivisi Brake that also has the light we have the SMI DUO part # SM99251 which would be a great option for your 2006 Chevy HHR. It also has the light indicator so that you know the brake of the toad are being applied. We like the DUO best because it's much easier to install and works really well.
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  • Installing SMI Stay-in-Play DUO Braking System SM99251 in 2018 Jeep Wrangler JL
    My contact at SMI advised that the Stay-in-Play DUO Supplemental Braking System # SM99251 that you currently have installed in your 2006 Jeep TJ can be installed in the 2018 Jeep JL Wrangler by cutting the JL's 8mm hard plastic line and installing the SMI 3/8-inch vacuum hose. SMI recommends also using a worm clamp for a secure connection.
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  • Supplemental Braking Recommendation for Flat Towing a 2014 Jeep Wrangler
    Yes, the SMI Stay-IN-Play DUO Supplemental Braking System # SM99251 has been confirmed as a fit for your 2014 Jeep Wrangler so it would work well for you. Check out the install video I attached for more information. I also attached a couple help articles on flat towing for you to check out as well.
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  • Best Flat Tow Brake System for a 2022 Ford Ranger
    The Demco SBS Stay-IN-Play DUO # SM99251 is my favorite braking system by far and the one I recommend installing on your 2022 Ford Ranger, especially if you'll be towing multiple times a year. This system has a bit more of an involved installation up-front, but after the initial installation you literally just have to connect the breakaway kit and flip a switch to get the system ready for towing. The Demco SBS Delta Force SM99242 (discontinued) is a good braking system as well, but I usually...
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  • Is One Time Fuse Blowing of SMI DUO Braking System Something to Worry About
    A one time fuse blowing of your SMI DUO part # SM99251 is most likely an anomaly that would be nearly impossible to track down. If you don't see the fuse blow again I'd just chalk it up to a bit of bad luck in that moment and not worry too much about it. I don't think your heat shield idea is terrible, if it would give you some peace of mind you may as well try it.
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  • Installation of Demco SMI Stay-IN-Play DUO in 2008 Jeep Wrangler
    For your 2008 Jeep Wrangler 3.8L V-6 the SMI (Demco) Stay-IN-Play # SM99251 is a great option and my favorite system. Demco did buy out SMI last year, but they kept their tech and engineers because it is an excellent product. I've attached a video of an installation we've done on a 2008 Wrangler so you can see where we installed it in front of the brake pump. You are correct there is very limited room on that model, but it will fit and work well for you.
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  • SMI Stay in Play Duo Supplemental Braking System Compatibility With 2017 Fiat 500
    The SMI Stay-IN-Play DUO Supplemental Braking System # SM99251 is a confirmed fit for your 2017 Fiat 500. It is my personal favorite system as well as a favorite with our installation team. This is because it is an easy installation that is extremely reliable. The system becomes plug and play after installation so you don't need to be concerned about adjustments or fit after the initial install. I'm confident you will be happy with this system in your Fiat. I've linked an installation...
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  • Recommended Supplemental Braking System for 2013 Chevy Sonic
    The supplemental braking system on your 2013 Chevy Sonic I highly recommend is the SMI Stay-IN-Play # SM99251 for this. This is a proportional braking system which is a one-time install which you can leave in so you'll never have to deactivate or re-activate it. The Stay-IN-Play uses an inertia sensor to detect when you decelerate which in turn will activate your Chevy's brakes. This system is made in the USA and comes with a 5-year warranty. I've added links to a number of video reviews...
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  • Does Demco Stay-IN-Play Duo Flat Tow Brake System Use Vehicle Brake Booster Vacuum to Operate
    Great question, Bob! The Demco Stay-IN-Play Duo Flat Tow Brake System # SM99251 actually activates the vacuum in your vehicle so the vehicle brakes work more naturally - it doesn't rely on the vehicle's vacuum system to operate. If your vehicle happens to not utilize vacuum braking then there are provisions for this on page 16 of the installation instructions.
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  • Will the SMI Stay-IN-Play DUO # SM99251 Fit a 2018 Jeep JL Wrangler
    The SMI Stay-IN-Play DUO # SM99251 is actually a universal supplemental braking system so it will be compatible with your 2018 Jeep JL Wrangler. If you check out the attached installation video of this system on a 2017 Jeep Wrangler you can see that the only time this system really connects to your vehicle is for the ground (to a bare metal surface) and your battery for power. At this time (February of 2018) we have not been able to test fit very many products on a 2018 Jeep JL Wrangler...
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  • Where is Fuse Located on Demco SBS Stay N Play DUO System
    The 15 amp fuse that you are looking for would be on the power wire that runs up to your Honda CR-V battery. It should be red in color and probably the closest thing to the battery. The kit would have came with a 20 amp fuse but if you lost it the style is ATO.
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  • Supplemental Braking System Recommendation for 2018 Chevy Sonic
    The best supplemental braking system we have for your 2018 Chevy Sonic is the SMI DUO part # SM99251. This is a permanent install kit which means you install it once and you're set and don't have to reset up a system every time you want to flat tow. It's our installers favorite kit because of how much easier it is to install over the other similar kits and because of how well it works. I attached an install video for this kit on a similar 2014 Chevy Sonic as yours. I also attached a video...
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  • Does Tow Mode of 2018 Jeep Grand Cherokee Affect Fuel Mileage When Towing
    Even if you could undue the shifting programming of your vehicle in tow mode you'd find that the fuel mileage is going to still be just as bad. The weight and wind resistance of your trailer is what is killing the mileage more than the way it shifts. Unless it's not letting you shift into overdrive on the highway the tow mode would not be affecting your mileage more than just towing.
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  • Will Heat be Concern with Demco SBS Duo Mounted Near Brake Booster
    Since you would plan to mount the Demco SBS DUO on a bracket near the brake booster that would be far enough from heat sources to not be an issue. You just wouldn't want it right near exhaust components as they get the hottest.
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  • Recommended Fixed Supplemental Braking System for a 2017 GMC Terrain
    I recommend the Stay-IN-Play DUO, part # SM99251. It's a permanently installed braking system, like you're looking for, so all you need to do is flip a switch to activate it when you're ready to tow. Instead of using a cylinder and bracket that pushes your Terrain's brake pedal the DUO's actuating cylinder mounts to the brake pedal arm and connects to the firewall. The actuator doesn't get in the way and doesn't need to be removed or unhooked at all. Just flip the switch back off and...
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  • Getting Power to SMI DUO Braking System on 2017 Ford Focus
    I spoke with a representative of SMI, and they informed me that when using their Stay-IN-Play DUO, # SM99251, you should disconnect the positive cable from the battery, not the negative cable, despite what the owner's manual says. Then you should run the power wire between the positive post and battery disconnect. I also asked SMI about the braking system being activated when the turn signals are used. They said it was likely that this was happening because the sensitivity knob is set...
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  • 20 Amp Fuse Keeps Blowing on the SMI Stay-IN-Play DUO
    I called SMI to see if this was something they had heard of before and my contact said that your 20 amp fuse should not be blowing when you pull the breakaway switch on the SMI Stay-IN-Play DUO # SM99251. What he said you can try to do is swap out the 20 amp fuse for a 25 or 30 amp fuse and check all of your grounds. He mentioned that anytime there is a problem with a fuse it is most likely the ground so that is a good place to start.
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  • Where to Make the Vacuum Connection on a 2014 Jeep Cherokee V6
    Since sometimes in vacuum line t-connectors there can be reducers installed in the t-connectors to reduce vaccuum signal I would recommend you install the check valve between the t-connector and the brake booster just to be on the safe side.
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