To see if this custom-fit item will work for you please tell us what vehicle you'll use it with.
Thank you! Your comment has been submitted successfully. You should be able to view your question/comment here within a few days.
Error submitting comment. Please try again momentarily.
Imagine prepping for your trip and having your braking system ready in less than a minute. With the RVibrake 4, the audio assistant guides you step by step, so there's no fumbling or guesswork, just a quick and reliable setup every time.
A braking system is a must when towing a vehicle behind your motorhome. Without it, the extra weight of your toad (towed vehicle) puts more stress on your RV's brakes, makes it harder to stop safely, and can even put your warranties at risk. Most states legally require one, and if you're ever in an accident, not having a braking system could leave you with major insurance and liability problems. Plus, without one you don't have a breakaway safeguard. If your toad ever disconnects, there's nothing to bring it to a stop.
If you choose the wired route, the most involved step may be drilling through the firewall if there isn't already an open pass-through. Once that's handled, the rest is simple. Clip on the brake pedal claw, plug the unit into your car's 12V outlet, press the "Auto Position" button, and follow the voice prompts. That's it. If you'd rather avoid drilling or running wires entirely, the wireless adapter keeps the install uncomplicated while still giving you full breakaway protection.
Second, it gives you a lot of flexibility. Moving it from one toad to another is simple. As long as you have a second vehicle breakaway kit (RVi97FR - sold separately) installed, the RVibrake 4 can be set up in another car in minutes. That means you can switch up which vehicle comes with you on your next camping trip. And if you trade in your toad down the road, getting the new one ready for this unit is a breeze.
The RVibrake 4 has a built-in inertia sensor that knows when your motorhome slows down. As soon as it senses that change, it presses your toad's brake pedal at the same time and with the same force you apply up front. From a gradual slow down at a red light to a hard stop in an emergency, the toad and the RV will brake together. That's what makes it a proportional system.
The in-cab wireless controller, called the Bullseye, lets you adjust the sensitivity of the inertia sensor to determine how hard the RVibrake 4 system will push on the brake pedal. 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.
If you're towing a hybrid or any car with continuous-power-assist brakes, all you have to do to use the RVibrake 4 is choose Active in the "Brake Type" setting on the Bullseye monitor.
The RVibrake 4 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 your vehicle to a stop.
This switch mounts to the front of your toad and plugs directly into the 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.
Supplemental braking systems draw power from your toad, and over long travel days that can slowly drain the battery. The Curt RVi Series Towed Battery Charger+ (RVI74FR - sold separately) solves that by letting your toad pull power directly from your RV while you drive.
It doesn't just charge. It also sends battery status information to your Bullseye Monitor, so you can see exactly what's happening in real time from the driver's seat. No guessing about your battery status or surprises when you unhook. If you're towing for full days at a time, this is one of those upgrades that adds real peace of mind.
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. If you'd like help installing the components for your flat-tow set up, check out our Installer Locator to find an installer near you.
California residents: click here
Customer Satisfaction Score:
92% were satisfied with this product
8% of customers were not satisfied
Ratings & Reviews
Super simple to use and the wireless bullseye monitor work great. The boot up time on the monitor is about 5 seconds.
From a towing perspective I worried about the system being too intrusive with braking. The RVIbrake performed perfectly. Light and heavier braking when needed and none on gentle stops. Its small and light so its perfect for us to be able to swap between tow vehicles.
The Curt RVibrake 4 was delivered today. A day late but the etrailer experts were very helpful and gave a lot of info. Christine was very helpful also. Ill be watching for sales or deals and place another order.
I have had the RVi3 break since 2018. It developed an air leak in the activator box which was not repairable, so I ordered the new RVi4 to replace it. The brake itself appears the same as the RVi3 but have had some internal upgrades resulting in faster response. The control pad has been greatly improved as it is a round smaller unit that takes less space on the dash, is more stable and very pleasant looking. The round puck that used to be required to be inside has been replaced with a much smaller repeater that goes outside the coach near the chassis batteries and is out of the way. I am reall pleased with the redesign by Curt/Lippert, the new owners.
The brake itself works well. The range booster’s effectiveness, however, is very spotty when installed as instructed. We’re in a 45 foot diesel pusher. Installing the booster in the engine bay just doesn’t work well; there’s way too much electrical noise to interfere with the booster causing the Bullseye to constantly lose connection to the RVi brake. The booster really should be designed to install in the coach and powered by something other than those cheesy little alligator clips that you’re supposed to clip directly to your chassis battery.
Kate F.
5/6/2026
Thanks for sharing your experience, especially with a setup like a 45 foot diesel pusher Mike. It’s good to hear the braking itself is working well, so let’s see if we can get the connection side of things cleaned up. On longer coaches, having the range booster in the engine bay can cause interference and lead to the dropouts you’re describing. We’ve seen better results when it’s moved inside the coach or to a more central spot. It can also help to keep the antenna vertical and not blocked by metal. We appreciate the note on the alligator clips too. They’re meant to keep the system portable, but we understand wanting a cleaner, more permanent power option on setups like yours, and we’ll pass that feedback along.
Love it, works great. Be prepared to spend more $ because if you want the charge indicator and breakaway to show on the display you need to buy both modules separately. Not mentioned anywhere in the description. Making it a pricey item. But it works great. Otherwise I would have given it a 5 star.
The system arrived in excellent working order with easy to read instructions. I have installed the system for a power on test and it worked great. I have not tested it on the road yet, but I have no doubt that it will provide the braking power needed.
I have not had the opportunity to try this braking system yet, however, I did phone customer support on two separate occasions while installing this system. They walked me thru the entire installation. I am so thankful for that. I look forward to trying this system shortly. I have no doubt it will work great.
Jesse (etrailer.com employee) here. I got my first look at the RVI brake system last week. My first impression was the box and packaging was very neat and clean. The portable system was extremely easy to set up. It talks to you and tells you what to do! This is perfect for DIYers or first timers that don't want to pay big $$$$ to have a shop install a braking system.This system uses the Bullseye monitor which is what really sets it apart. The bullseye is a touch screen and it does all kinds of stuff like real time towing info, diagnostics and braking adjustment just to mention a few.
I recently got to host a first look for this system and I gotta say, its pretty cool. Its small and lighter than similar systems. It can be a little clunky the first time you install it but once you get through that first install, it becomes a lot easier. Once plugged in, the unit will talk you through how to calibrate and will notify you if there are any issues. If there is, the Bullseye will tell you what the issue is and what needs to be done. Cuts out a lot of guess work. The only thing that needs to be installed in the breakaway. I highly recommend this system to someone who wants something easy to use with next to no install.
Imstallation very easy. Operation easy once you do it a few times.
We just got these added to the site, so I was really excited to go to the first look training so I can learn more. I love that this RVI system is not as bulky as the other portable systems I have had in the past. It is very simple to install, and I really like how it talks back to me, just like my kids Ha Ha! The Bullseye screen is definitely a bonus, it gives peace of mind while flat towing. If things start acting up it alerts you.
Very good service, fast response, and willingness to help. The only reason for four stars is that the order was shipped via USPS, which was very slow and provided minimal updates.
All items arrived in a timely manner. All parts received, in process of installing. So, far all things are good to go.
So far so good.easy to install and set up
Works great!
Unhappy with the product and Curt/RVI customer service. The RVI 4 seemed to setup and work fine on the first leg of the first trip, but started giving me issues on the second leg of the trip. At this point my wife and I are driving a MoHo and a Toad separately from Hot Springs, AR to Dallas, TX then to New Orleans, LA because this product failed and the manufacturer won’t take a little initiative to manually pick a new unit from their warehouse stock and ship it overnight to me where I am staying for the next few days. Curt just wants to blindly let the request flow through their computer and shipping systems, rather than use a little human intervention to support a $1,500 product that is ruining a trip we have been planning for months. That is the customer support frustration.
The bigger issue is the product. This is a SAFETY component. After getting error codes, the only info I could find online while traveling indicated the error codes (04-07) were likely due to temperature affecting the solder joints on the circuit board. See the video posted on YouTube by Curt on RVI 3 (there is very little info on RVI 4) error codes. The online recommendation is to bring it inside and let the temp acclimate, then it should work. This is not acceptable! If this circuit board issue is accurate, it is a critical QA and SAFETY issue. While flat towing, the inside of the toad will get hot and cold, therefore the risk of the RVI Brake failing and not serving its purpose is a huge concern - especially in a breakaway situation.
I could not find a phone number for CURT on their website, but etrailer was kind enough to provide it. When I called Curt, they said it was likely low voltage in my toad like the video stated. “Just plug it in inside the MoHo and see if it works.” I expected an engineering answer like “the unit is designed for a minimum of 12.x volts to reliably operate…” it didn’t work in the MoHo either. It just ran the air compressor non-stop when connected inside the MoHo which produces another error code.
When connected in my Toad, I had my charge line connected, MoHo running, toad batteries freshly charged from driving, and a 12.8v reading in the toad. I have a 14 gauge power supply connected directly to my toad battery. The documentation I found indicates the full load current should never exceed 3A, so the voltage drop in my power supply line should be negligible for this situation.
So, with an error code for bad electronic board solder joints, CURT’s SAFETY solution is to warm it up for 15-20 minutes, hope it initializes, and blindly trust that all those issues only exist when you are initializing the unit — not while towing! For Low voltage, they provided no design spec. If it works in the MoHo but not the Toad, it is the customer’s issue in the Toad, but no voltage or motor starting voltage drop specification is available for me to use.
Still trying to determine if I will ask for a refund or take the replacement after I get back home. Without some rock solid explanations, I am very leery of the product’s quality and its SAFETY reliability.
Lazer S.
11/4/2025
Sorry to hear all your troubles, Shawn. I tried contacting Curt and all I could get out of them was you needed to either have them send a new one and they would take the one you currently have or just return it for a refund. I was really hoping they could tell me more than that so I could get you back to at least some kind of normal, but I struck out with two different reps. They did say they think it's faulty though (they remembered you calling them), so let me know how you wish to proceed with it. I will do my best to get you taken care of. Again, I sincerely apologize for your troubles.
I would give the brake system a much higher mark if I had purchased it at a more reputable store. It is unfortunate that a retailer itself has to spoil the rating of an item.
The brake system appears to be functioning properly. But the e-trailer itself is not good. When I purchased the system, etrailer said it would be delivered in under a week. Well, at the 2-week mark, I called them and asked about it; they said, basically, "Oh, well, too bad." But yes, it did finally show up at the 3-week point.
I will never buy anything from etrailer again if I need it in a certain time frame, as obviously,y they will not honor the schedule they set.
Nick S.
12/29/2025
I am glad the brake system is working, but I am sorry about your experience with us. With the weather delays we experienced shipping for all products was effected and I apologize that that was not communicated properly.
$1600 is a lot of money, but worth it if this product worked as advertised. right out of the box, I got an error code 1, which for this unit is an issue with a micro switch at the base of the cylinder. This isn't the shadow controller so, no there isn't an umbilical issues. The only hookups are the power and breakaway switch. It has been 6 weeks of torturous phone calls and e-mails to Curt and LCI customer support and I'm still no closer to a functional unit. Tech support is nonexistent so if you have a problem send it right back because the warranty is apparently only good for filling your trash can.
I had a generation 1 RVI brake that lasted for years without fail, but was hoping the upgrades promised with this redesign would simplify setup and improve the braking functionality. the only improvements appears to be a fancy racing stripe and unnecessary added complexity.
If you silence the alarm every time you brake, it does work so I give it 2 starts.
Gwendolyn Y.
5/12/2026
Hey, Mike. I'm really sorry to hear all that you're going through. I'm going to be reaching out so I can get this sorted out for you.
Do you have a question about this Flat Tow Brake System?
Info for this part was:
At etrailer we provide the best information available about the products we sell. We take the quality of our information seriously so that you can get the right part the first time. Let us know if anything is missing or if you have any questions.
Kate F.
11/26/2025
Glad to hear that they made the right changes Randall! What kind of RV do you have, any fun trips this year?