Are You Braking the Law? By Mark Polk

Hi my name is Mark Polk. I am the owner of a company called RV Education 101. We produce videos on how to use and maintain Recreation Vehicles, and I am the author of a book titled “The RV Book”. I started the company because I was concerned about the lack of education and safety awareness for the RV consumer. To view our complete line of products please visit our website at http://www.rveducation101.com/.


Recently we teamed up with National Interstate Insurance Company (NIIC) to provide RVers with educational material to make all of your RV experiences safe fun and stress free.

This article focuses on an important topic if you plan to tow a vehicle behind your motorhome; a topic that is sometimes overlooked, and seldom talked about. The topic is supplemental braking systems. It’s not about what supplemental braking system you have, it’s the fact that you have one!


One requirement for towing a trailer is that the trailer must have a braking system that works in conjunction with the tow vehicle brakes. Why should this requirement be any different for a motorhome towing a vehicle? In reality its not, but most people just assume you don’t need a supplemental braking system for the vehicle you’re towing. Some reasons for this assumption are:

1) Because of the size of the motorhome there is no need for a supplemental brake system on the tow vehicle.
2) People assume the vehicle they are towing is much lighter than it really is.
3) Braking laws are not always enforced by individual U.S. states and Canadian provinces.
4) Nobody took the time to educate the RV consumer on the requirement for a supplemental braking system.


Putting assumptions aside, let’s take a look at some of the facts surrounding supplemental braking systems:

1) The brakes on a motor home are designed by the vehicle manufacturer to stop the weight of that particular vehicle, not the additional weight being towed behind it. This additional weight adds a substantial increase to the distance required to stop safely. Some motor home chassis warranties are voided if you tow amounts over 1,000 pounds without a supplemental braking system.

2) The vehicle you’re towing probably weighs more than you think it does. You need to take your towed vehicle to a set of scales and have it weighed. Make sure it is fully loaded with everything that will be in it when you are towing it. After you weigh it, double check to make sure the receiver on the motor home is rated to tow that amount of weight and that you aren’t exceeding any of the motor home weight ratings, like the Gross Combined Weight Rating (GCWR). The GCWR is the maximum permissible weight of the fully loaded motor home and the fully loaded towed vehicle combined. Most RV chassis manufacturers base their GCWR on the assumption that a supplemental brake system is being used.

3) Most states and Canadian provinces do have their own laws on the requirement for brakes on a towed trailer. The word trailer also applies to a vehicle being towed behind a motor home. These laws are normally based on the amount of weight being towed. Add to this your insurance company may not cover you in the event of an accident involving a vehicle with no braking system.

4) It’s sad to say but many times the RV consumer is not properly educated on the requirements for a supplemental braking system on the towed vehicle. And the most important reason for a supplemental braking system is for your safety and the safety of others.

Now that you have a better understanding of why you need a supplemental braking system, you need to decide which type is right for you.

(Photos Courtesy of Blue Ox)





There are many different types of supplemental braking systems available on the market today. These types include surge, hydraulic, air and vacuum. Some are very simple to install and use and some are much more complex. I recommend you talk to a knowledgeable RV dealer about which system would work best for your particular needs.

I personally like the idea of keeping it simple and decided the best system for me would be a portable type braking system. I decided on this type of braking system for several reasons.
1) It’s portable and it works on almost any towed vehicle with power brakes.
2) It doesn’t require any modifications to the existing brake system.
3) It’s easy to install and use

Regardless of the type or model you choose, being able to stop completely, in less time and a shorter distance, will give you an added sense of safety whenever you’re towing a vehicle. And it’s the law in most cases. Most importantly, a supplemental braking system SAFELY reduces the stopping distance and helps to protect you, your loved ones and the safety of others.

Q & A
Question: Where can I find state and province laws regarding weight limits for towing without supplemental brakes?
Mark Says: For safety reasons I recommend you consider a braking system regardless of the vehicle weight, but here is a link showing specific weight limits.
http://roadmasterinc.com/products/braking/map.html

Question: Is one type supplemental braking system better than the others?
Mark Says: It really depends on your particular needs. For example do you plan to tow the same vehicle all the time or will you be towing different vehicles? Will you be doing the installation yourself, or will it be done by somebody else? Is the system going to involve tapping into your vehicle’s brake system? What kind of warranty does the braking system offer? I recommend you talk to your RV dealer about which system is suited best for you.

Question: Can you tell me where I can go to research some of the different types of braking systems available to the RV consumer?
Mark Says: Here are some links to some of the manufacturers of supplemental braking systems. I apologize to any manufacturers I may have left out.

http://www.roadmasterinc.com/index.html
http://www.usgear.com/unified_tow_brake.htm
http://www.blueox.us/
http://www.brakebuddy.com/index.shtml
http://www.tow-v-aire.com/
http://www.towbrake.com/option.html
http://www.m-gengineering.com/index.html
http://www.smibrake.com/
http://www.viprv.com/index2.html
http://www.readybrake.com/
http://vasebrake.com/site/590961/page/45031


Happy Camping,

Mark J. Polk

Copyright 2007 by Mark J. Polk, owner of RV Education 101

RV Expert Mark Polk, seen on TV, is the producer & host of America's most highly regarded series of DVD's, videos, books, and e-books. http://www.rveducation101.com/.
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May RV Questions & Answers by Mark Polk

*NOTE: At Mark's discretion, material might be edited to suit a wide audience. Due to the large volume of material and correspondence we receive, individual replies might not be possible, nor can we acknowledge receipt of submitted material. Selected questions will be answered in future issues of our RV Education 101 newsletter and on our site. Thank-you for your understanding.

Q: We have a Pop Up and my husband and I can never seem to back it in to the camp sight where we want it to go. Do you have any advice or ideas?

Mark says: I have a method that has always worked well for me with two people working together. First decide who will drive and who will give directions. Let’s say your husband is driving. For this to work you are his eyes and he needs to do exactly what you tell him. When you are ready to back it in, you stand in front of the vehicle where you can see the trailer and communicate with your husband. He puts his hand on the top of the steering wheel and slowly turns the wheel in the direction you tell him. If you want the back of the trailer to go to your right you tell him to turn the steering wheel to the right. If you want it to go to the left tell him to slowly turn the wheel to the left. Don’t get upset if you need to pull forward and start over. With a little practice you’ll be backing like the pros. There is an excellent video available that not only demonstrates methods for backing a Pop Up, but it covers everything you need to know about using Pop Ups too. Pop Up video

Q: After we decided to buy a travel trailer the dealer told us we would need to spend another $1,000 dollars on hitch work. Isn’t this a little unreasonable?

Mark says: The dealer should have explained the importance of proper hitch work during the sale. It is for your own safety and the safety of your loved one’s. If your particular purchase requires a weight-distributing hitch, dual cam sway control, electric brake control and wiring then 1,000 dollars is not unreasonable. Any reputable RV dealer will not sell the trailer without the proper hitch work.

Q: I have heard people talk about the 75% rule of thumb for towing. How does this work?

Mark says: There is some confusion on this subject. A lot of people say that you take the manufacturers tow rating for a vehicle and multiply it by 75% and this is the maximum weight you should tow. For example a tow rating of 8,000 pounds X 75% = 6,000 pounds. The 75 % rule is designed to build in a margin of safety. The way that I understand it and apply it is that you take the Gross Combined Weight Rating (GCWR) of the tow vehicle X 75%, and the Gross Vehicle Weight Rating (GVWR) of the tow vehicle X 75%. Once you determine this you subtract the two and this is the maximum weight you should tow. Using the same example above that vehicles GCWR is 14,000 pounds X 75% = 10,500 pounds. The GVWR is 8,800 X 75% = 6,600 pounds. 10,500 minus 6,600 = 3,900 pounds. I apply this rule if you plan to tow in high elevations. A gasoline engine looses 3 to 4 percent of its power for every 1,000 feet above sea level. The 75% rule compensates for that lose in power.

Q:My 2006 Toyota Tundra Quad Cab truck has a GCVWR of 11,800 (12,200 from another source), let's be conservative and say 11,800. The truck does have factory installed towing package. Tow rating on truck with tow package is 7100lbs according to owners mannual. Trailer has dry weight of 5190 and gross weight rating of 6500lbs. My estimates on cargo and add on's, I have estimated at around 850 to 900lbs. If we did any dry camping it would be very rare. So I'm not allowing for a lot of water weight.

So, loaded trailer weight should be about 6040lbs. Looking at it from this point I have almost 1100lbs of slack. But from at GCWR I'm pushing the envelope on weight. I do have a oil cooler with tow package. I have a prodigy brake controller, and I'm going with your recommendation and purchase an "Equalizer" hitch. They are kinda of high $$$, but I feel it will be money well spent. My truck also has a tow mode on the transmission. It takes it out of overdrive and runs the truck in 3rd gear. (There goes gas mileage!!)

The Jayco trailer I am looking at and the weight of the truck, put me at 98% of the GCVWR. I know the lower percentage the better, but what I can't get a straight answer on is being at 98% will the truck still pull O.K. I don't want to put the truck in a bind, and I don't want to spend 20 minutes trying to get up a hill either. I have weighed my truck on a scale as recommended. It was loaded and full of gas. I probably went a little overboard putting fire wood in the bed to get some extra weight. Just trying to figure on high side. I have also taken dry weight of trailer and have added for propane, hitch weight, some water, and personnel food and gear. (Food & Gear I used about 350lbs.) Just some added info. Based on the length of the wheel base of my truck. I'm just about at the maxium on trailer length too. I am going to purchase weight distribution and sway control hitch.
I just can't get a clear answer on towing ability at these weights from
anyone. You're not trying to sell me a travel trailer, so any information you can
provide me will be helpful.

I also have purchased your video series on RV's and have gained a lot of information. This is our first RV and we have a lot to learn. We need all the help we can get.

Mark says:I had a chance to review the information you sent. I have always said if the tow vehicle tow rating is higher than the trailers GVWR you are in pretty good shape (as long as you don't overload the trailer). And the key to the GCWR is to keep it below the GVW of the combined truck and trailer which you are, even though it is at 98%, it is below. If you plan to pull the trailer in the mountains a gas engine will loose 3 to 4% of its power at higher elevations and you may want to re-calulate your figures.

Copyright 2007 by Mark J. Polk owner of RV Education 101

RV Expert Mark Polk, seen on TV, is the producer & host of America's most highly regarded series of DVD's, videos, books, and e-books.
http://www.rveducation101.com/