Driving an RV with Air Brakes: All You Need to Know

I was very curious why driving an RV with air brakes is more strongly suggested than hydraulic ones, so I spent some time researching it. Apparently, there are several types of motorhome, and there are a lot of things to consider before I can fully channel my inner vagabond. 

Why is driving an RV with air brakes highly suggested? Air brakes are considered safer because of the lack of fluids to make it run and reduces the fear of overheating leading to brake failure. It is activated on pressured air and has a secure safety system with air tanks and a sound alarm that assists in stopping in the event of an emergency. 

That is just the tip of the iceberg. In this article, you will read a course about RVs and air brakes; the advantages and disadvantages of driving one; what a special license is, and what general information you should know before hitting the road. 

What you need to understand with RVs and Air Brakes

RV Classes

Class A

The largest motorhome built on heavy-duty frames, can range from 29 to 45 feet long and weighs anywhere between 33,000-36,000 pounds. It is considered to be one of the most luxurious RVs and features all the amenities of home. It is run by gas or diesel around 8-10 miles per gallon and is often operated by air brakes because of its size and weight that makes stopping difficult.

Class B

Also known as camper vans, and the smallest RV class size that ranges from 18-24 feet long. It is much like an oversized van that is designed to be tall enough for the average height passengers to stand upright. It is livable but doesn’t give much space compared to Class A RVs. It can house a kitchen, living room, bathroom, and with the toilet and shower combined in one space. This is considered to be the easiest RV to drive which is most common for aspiring vagabonds and usually operates on hydraulic brakes.

Class C

The middle ground between Class A and Class B motorhomes. Ranging from 33 to 39 feet long: it can give you more space than a class B while housing almost the same amenities in a Class A motorhome. It is built on a truck or van cutaway chassis that operates on a gas-powered engine, a hydraulic brake, and sometimes an air brake. 

Class B+

Resembles a class C motorhome with a cab-style front and is considered to be a hybrid between Class B and C. It is much shorter in height and length but wider than a Class B motorhome. It ranges from 17-30 feet and can offer the same amenities a Class B motorhome can house but with a little bit extra space. It also has good gas mileage between 10-25 miles per gallon and is often used for entertainment but without any sleeping space, you can lie in after the fun. 

Relation between RV and Air Brakes

RV or also referred to as motorhomes are often debated between two kinds of brakes: hydraulic and Air. 

Hydraulic brakes function through hydraulic fluid while air brakes rely on air pressure. Heavier motorhomes suggest air brakes because of its safety precautions and strong stopping force. The heavier the vehicle, the more work brakes do to stop it and the more heat it absorbs due to friction. With hydraulic brakes, too much heat isn’t a good thing because it moves the hydraulic brake fluid and heats up that can turn to steam and result in spongy pedal and brake failure.

Air brakes, on the other hand, are designed for heavy vehicles because it relies on compressed air to make the vehicle stop that makes leakage or lack of hydraulic fluid not a concern. However, although air brakes are known for their superior stopping force, driving on air brakes isn’t as easy compared to RVs on hydraulics. Hydraulic brakes are what’s used on cars and vans used  today, so we are very much knowledgeable about these, that is why some states require a special driver’s license before you can drive a vehicle on air brakes.

Although safety is often the reason why other motorhomes push for using an air brake, another reason is because air brakes require less maintenance compared to hydraulics. Because air brakes function through air use, replacing fluids and fear of not having enough is one less trouble to think of. However, moisture can be trapped inside your air tanks that is why you must drain your air tanks and filter daily. Although a little moisture does not affect the system, excess water will, and might cripple the life of your brake components. 

Advantages and Disadvantages of RVs with Air Brakes

Heavier trailers require air brakes because of its reliability and ease in stopping huge vehicles. To stop a huge vehicle, friction is created and heat is produced. As I covered before this heat can cause the hydraulic liquid to boil and could eventually lead to serious problems if not properly replaced or maintained. 

Major advantages and reason for having air brakes on your mobile home:

  1. Air brakes are tolerant to minor leaks because it has a compressor with air filters that secures clean air  running in the engine. Sometimes air contains water vapor that condenses into liquid water which is why another part of the air brake is a supply reservoir called the wet tank. Air valves are installed in the tank to prevent this from entering the brake chambers.
  1. Air supply is unlimited and you won’t have to worry about not having enough hydraulic fluid while you enjoy your RV life. Lack of hydraulic fluid will destroy your hydraulic pump which could lead to rusty and harder braking.
  1. Air brakes have low-pressure sound alarms. In the event of any air leakage or excess water, the warning activates when the system pressure drops to 55psi or greater. 
  1. Air brakes have better-stopping power because of spring brakes. This applies a braking force to the vehicle and stops it automatically in the event of system air failure. This means not only are you warned by the sound alarm, your vehicle will stop and you wouldn’t have to worry about hitting anything sturdy to do that.

Major disadvantages and reason why you might want to skip air brakes:

  1. You have to be mindful of the weather because air can bring water droplets and might freeze in cold weather. Ice in air brake valves can happen and this will hinder the brakes from working.
  1. Air brake system is complex and therefore requires learning which is why some states would ask for a license before you can operate in their area. 
  1. Air brakes are noisy because instead of fluid, it emits compressed air to actuate the brake pads.
  1. Air brakes are not time efficient because it needs to have airflow to make the brakes work. Air travels into a series of pipes before it stops and would require a few seconds lag time compared to hydraulic braking. 

According to The Commercial Motor Vehicle Safety Act of 1986, the state shall authorize a person to operate a commercial motor vehicle only by issuance of a commercial driver’s license. However, a commercial driver’s license or a CDL is not enough for other states. Other states would require an air brake endorsement, pass series of knowledge tests, and skill exams before you can get the required special drivers license. 

Below are 3 license classifications as stated in the Commercial Motor Vehicle Safety Act:

Class A: combination vehicle with gross vehicle weight rating (GVWR) of 26,001 pounds or more, provided the GVWR being towed is in excess of 10,000 pounds

Class B: single vehicles with a gross vehicle weight rating of 26,001 pounds or more, or any such vehicle towing a vehicle not in excess of 10,000 pounds

Class C: single vehicles with a GVWR of less than 26,0001 pounds if the vehicle is: transporting hazardous materials requiring placarding; is designed to transport 16 or more passengers, including the driver; or, is a school bus

Source: http://www.dot.state.pa.us/Public/DVSPubsForms/BDL/BDL%20Fact%20Sheets/fs-cdl.pdf

You will also have to pass Knowledge Tests for the licenses, restrictions, and endorsements you wish to have. To obtain such a license, you must first pass the 25 question written Knowledge Test and Skills Test before you can acquire the Air Brake Restriction Removal which permits you from driving vehicles with air brakes.

Each state has its specification for its licenses and regulations but the information above is a fact sheet of the CDL (commercial drivers license) as a whole. 

Importance of weather when driving RVs with air brakes

Compared to houses, RVs are more exposed to different weather conditions. You can park in an open field and feel the intense rain, snow, and heat. But because air is always present, it is generally forgotten. Remember, air is the main source of your air brake system therefore knowing how to deal with these weather changes is very important.

Wet Weather

Living the vagabond life means first-hand experience of what rainy days are like outdoors. However, since air brakes function on air, its byproduct is water, and excess water will join with some of the oil a compressor brings in, thus being collected and stored at the bottom. This will accumulate and become a sludge that would enter the braking system and cause trouble with valves and other parts. That is why it is important to drain your air tank every day.


Water that is stored at the bottom of the tank can also freeze and ice can block air from reaching the brake mechanism, thus it is suggested to buy an alcohol evaporator and alcohol injectors to prevent this from happening. Alcohol acts as an anti-freeze and lowers the freezing point of the moisture collected from the air system. 

Now, weather isn’t the only thing you have to be mindful of, especially when driving an enormous vehicle with air brakes. However, if there’s common information that’s been passed on, it’s to always switch off your air condition when traveling on mountain passes or bumpy roads regardless of the brake your vehicle has. The air-condition will add up to the heat in the system for several bumpy stops and continuous braking. Keep in mind that there is a delay every time you hit the brake pedal, therefore you will have to consider a half-to a full second-time pass before the brake is applied. Lastly, consider a safe speed whether you’re going downhill or uphill. This continuous braking will overheat your brakes and we wouldn’t want another contributing factor to that.

2 Common mistakes when driving RVs with air brakes

If you’re checking this article out, you’re probably planning to buy or rent an RV and someone may have suggested that driving one with air brakes is the best deal. I know that you’re very excited to start your RV adventure, but here are some common mistakes that you should be aware of:

Skipping RV driver training lessons

Driving an RV especially those using air brakes requires special knowledge and skill, and relying on your driving skills isn’t enough. An older gentleman purchased a huge new motorhome and decided to skip class because he felt there’s no need to. He had to pull over and fuel up in one of the truck stops. Because he failed to consider the time it takes for the RV to stop, he cut the turn, hit the pumps, and caused fire. Yes, his newly bought RV and the pumps were totally ruined.

Sand-Clogged Air Filter

There is what we call “valley fever” where San Fernando or Los Angeles residents call those who suffer from respiratory problems when inhaling the dirty air of California hinterlands. Going on an RV adventure with air brakes requires you to check your air filter when visiting these sandy areas. Sand and dust can clog your air filter and being stuck in a sandy deserted area is just straight out of a horror movie, and I’m sure you wouldn’t want that.

The World at your Own Pace

Seeing the world at your own pace and time is wonderful, but there are several things you need to consider before doing so. To be on track, I suggest writing down all the states you want to visit, and taking time to research their set of rules before venturing on that endless road trip. It would be wise to have a notebook you can pull out while on the road deciding where your next stop will be. Also, it would be better to learn and get to know your RV most especially its composition for safety measures. Yeah, we’ve already accomplished that air brakes are awesome for having its alarm system, but you can never be too careful. Besides, being alone in a deserted area is definitely the first fifteen minutes of any suspense and horror movie you surely don’t want to be in.


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