Braking Systems Information

We hear so many claims from RV owners about the need for or that there is no need for a braking system when towing a vehicle. The usual argument begins with "My State/Province does not require a Braking System on my towed vehicle”. One can argue with that statement with the fact that most trailers pulled behind a truck or van require a braking system. At the very least a break away system is required, often before the trailer leaves the sales lot. What makes a towed vehicle any different?

There really are four areas to look at (possibly a fifth – more about it later)

• RV Chassis Maker requirements
• State & Provincial Brake System Requirements
• Newton’s Law of Motion
• Peace of Mind

 

RV Chassis Makers:
 All Chassis makers have a requirement that anything towed over 1,500 lbs. (680 kgs.) require a braking system. The chassis makers design the chassis to stop the chassis and RV built on it, but the variety of towed vehicles and trailers make it impossible for them to design braking systems that will safely stop the combination. A utility or travel trailer will have braking on the axles which will require a control in the RV. It is a logical assumption that a towed vehicle in this situation is really no different than a towed trailer.

State & Provincial Brake System Requirements: 
 Almost every state and province has some requirement for a supplemental braking system for a towed unit. Most set a weight limit or threshold to determine the need. Some Towed Vehicle Braking System makers publish a chart or map in a paper format or on their website, setting out the specific requirements on a state by state or province by province basis. While your home state may not have a requirement, what happens when you travel through that state? Do you need to comply? I am reminded of the requirement in many states that headlights must be on when the wipers are on. That requirement may not be the rule at home but it applies when traveling in that state. What makes Towed Vehicle braking any different? 

Newton’s Law of Motion:
 Newton law of motion states that an object remains in motion until acted upon by an outside influence. Thus the towed vehicle will continue to roll at highway speeds until some force, braking or friction or some other factor, slows it down. The force of the speeding tow vehicle will "push” the RV while it is braking, greatly increasing the distance it takes to stop the combination. A properly set up braking system  designed to stop the towed vehicle leaves the brakes on the RV with the task of braking just the RV. In an emergency braking setting that extra distance can be deadly.

Peace of Mind:
 If the purpose of a RV is to travel and explore, taking a vacation or moving your home all around North America, why burden yourself and your family with the stress of worrying about safely stopping? Often time is not the object of the travel, the stress from life away from RVing, melts away when you RV. Why add to it with a vehicle that may not allow your RV to stop in time when braking. The addition of a Supplemental Braking system reduces stress.

The "Legal” Factor:
 Should a RVer be involved in a collision, especially where there is questions about the cause or injury, then the legal teams will look at the situation and question whether all reasonable efforts had been taken to reduce risk. A vehicle without a Towed Vehicle Braking system would certain raise the bar and likely incriminate the RVer for not taking all reasonable efforts. The lawyers will have a field day.

So what is the bottom line?
 A reasonable person would conclude that a Towed Vehicle Braking system is a wise addition when towing a vehicle behind a RV.

 

 

What type of Towed Vehicle Braking System should be acquired?
 

Before talking about them it is important to understand that almost all towed vehicles have power brakes. The system used to reduce the force that would otherwise be required to apply the towed vehicle’s brake, may be vacuum assist (most common), hydraboost (often on heavier trucks) and hybrid systems using electrical-mechanical assist. Vacuum systems use the vacuum created from a running engine to store vacuum in a vacuum brake booster mounted on the firewall immediately behind the brake master cylinder. Hydraboost systems use a similarly located booster however the assistance is provided by the vehicle’s power steering pump and a large spring which is part of its design. Hybrid systems vary with all providing some assistance to overcome the large amount of force required to move the brake pedal to activate the brakes.
  
There are two primary styles of Braking Systems: Portable or Built-In. Each has its advantages and disadvantages.

Portable Units (often called Brake Systems in a "Box”)
The portable units can be easily moved from vehicle to vehicle requiring that the breakaway system wiring be installed on each vehicle. Many (we’d suggest most) also require a separate power supply socket to handle the power requirements of these systems. The disadvantages include the need to place them in on the towed vehicle’s driver floor area and connect them to the brake pedal securely. These systems also require connecting the power and breakaway wiring each time the system is installed to tow.  Most require that the vacuum assist be depleted by pumping the brake pedal 3 or 4 times, with the engine off, to eliminate the assistance that the vacuum booster provides. The brake pedal in these system requires considerable more force to depress. This is called a "dead (brake) pedal. Some of the newer systems automate this process by the towed vehicle braking system going through this pedal depressing as part of its set-up process.  One of the largest disadvantage of these system is the need to place the system in each time the system is used and out each time the vehicle is driven. Many require the driver’s seat be moved to act as a support/restraint to the system, which can be a problem if the vehicle does not have a seat memory position. Newer braking systems do not need to have the seat moved into place, greatly enhancing the utility of these braking systems. Others monitor or provide coach supplied power to charge the towed vehicle battery while being towed. Some have integrated monitoring of the towed vehicle’s tire pressure on its monitor panel, so that the RVer knows more about what is happening with the towed vehicle as it is being towed. 

Built in System:
The systems that are installed in the tow vehicle simply require an electrical connection and/or an air connection between the towed vehicle and the RV, in addition to the break-away connection. There usually is no setup procedure other than those that do not use the towed vehicle’s power brake assist, to bleed that vacuum off. Those that do not require the bleed off of the vacuum consider the towed brake system to be "live” and they simply augment to vacuum already in the brake booster when the Towed Vehicle Braking system is in use.
Some air powered systems require a mounting bracket and air hose to be installed. In this case the cylinder is removed each time to drive the tow vehicle. There are variations.

The chart that follows is taken from our book: "All the Stuff You need to Know about RVing” and is used with permission.