10 Important Facts About Bus Brakes

Before heading off on your bus adventure, there are only a few things more important to consider than the condition of your braking system. To do that, first, you need to understand the difference between brakes on your bus and your typical vehicle.

1. Air Brake Systems

Buses use Air Brake Systems, rather than hydraulic systems as found in other vehicles. Using compressed air to make the brakes work, the heart of this braking system is the compressor. Often directly attached to the engine, it can also be found engine mounted or belt-driven. Essentially, it turns every time the engine does and is fed oil directly from the engine’s pressurized oil system.

You will find there are air reservoirs positioned in several locations and plumbed together with one-way check valves. These store the pressurized air in readiness to draw from when required in the brake chambers.

bus air brake

2. Low-Pressure Warning Signals

Your bus will have a low air pressure warning signal. This consists of a warning signal that will come on to alert you before the air pressure in the tanks falls below 60 psi.

3. All Buses Must-Have Emergency Brakes

All buses using hydraulic brake systems must be equipped with emergency brakes and parking brakes. These are required to be fixed by a mechanical force and typically use spring brakes. If the air pressure is removed, the springs apply the braking system. You will see there is a parking brake system in the cab of the bus that allows the driver to let the air out of the spring brakes and enables the springs to put the brakes on. Alternatively, if there is a leak in the air brake system causing a loss of air, this will also cause the springs to apply the brakes.

4. Stop Light Switch

Obviously, it is vital to ensure drivers of vehicles traveling behind your bus are aware of your intended movements. They must be warned when you apply your brakes. The air brake system has an electric switch that turns on via air pressure, ensuring the brake lights go on when you step on the brakes.

5. What’s That Hissing Sound?

Ever noticed that weird hissing sound that buses make when it pulls up? Bet you have sat at a bus stop one time or another thinking, ‘Why do buses make that noise?’. Well, I hate to break it to you (pardon the pun), but that annoying hissing sound happens because instead of the braking system using fluid like a car does, the bus system uses compressed air to activate the system. There you go, mystery solved!

6. What Makes Air Brake Superior?

Air brake systems are preferable to hydraulic brakes for several reasons. Firstly, the air brake systems can tolerate small leaks. Importantly, the parking brake system also ensures a fail-safe emergency braking system, although it is true to say that some hydraulic systems accommodate for this also. If you are traveling across mountainous areas, you will find that hydraulic brakes may just not cope and become overstressed, whereas air-brakes can withstand this pressure in a much more robust way.

7. Coming to a Normal Stop

When approaching your typical course of stopping your bus, simply push the brake pedal down. Focus on controlling the pressure so the bus comes to a smooth and naturally safe stop. It is likely you may have a manual transmission, especially with many of the older cruising buses so if this is the case, it is important not to push the clutch until the engine RPM is down at almost an idle. As soon as you are stopped, select a starting gear.

8. Emergency Stops

Naturally, if a vehicle suddenly pulls out in front of you or an animal or other object appears on the road ahead, your human reaction is to slam down on the brakes. While this may be an adequate response if there is plenty of room to slow the bus and come to a stop, there are some safety factors to consider. There are two types of emergency stopping methods, the controlled braking or stab braking.

In controlled braking, the idea is to apply the brakes hard, keeping steering wheel movements very small. If the wheels lock or you need to make a larger steering adjustment, release the brakes then reapply as soon as you can. Stab braking sees you apply the brakes all the way then release when the wheels lock up. Immediately as the wheels start rolling, hit those brakes again.

9. Anti-Lock Braking Systems

In newer or modified buses, you may find you have an Anti-Lock Braking Systems (ABS) braking system. This will help you avoid wheel lock-up as it engages a computer system that anticipates a possible wheel lock, reducing braking pressure. In this case, there is no need to pump the brakes to stop the vehicle

10. Check your brake system regularly

It is naturally pretty important you get into the routine of measuring and adjusting your brakes. You may be surprised that is fairly easy and quick, so make sure you put it on your list of must-dos as you are cruising in your bus. You will note “Brake Check Area” signs often found on roadsides and typically at the top of the biggest hills in mountainous areas. When you have a whole lot of weight behind you, it's a pretty good idea to be certain you have the power to go downhill safely.

To drive certain types of heavy vehicles such as a bus, you must apply for the proper endorsements only if you plan to operate your bus as a commercial business. Otherwise if you convert it to an RV and are using it for private use, you don't need a CDL. However, it doesn't hurt to get the proper endorsements more so to educate yourself on how you should operate a large vehicle with air brakes. If you do decide to get your endorsements from the DMV you will need to learn the material contained in the DMV’s CDL Air Brakes section of the study manual. To be eligible for the air brake testing, you should learn and study about how air is maintained in the system and the pressure conditions required to drive under.

Note: Always check with the DMV in your state as rules and regulations change constantly.

This article was submitted by Nadeem Ghori who is the Content Manager and Web Developer at Webplex Inc with over ten years of professional experience. He's an expert in e-learning and online course generation.



Fan-Tastic Fan or Maxx Air Fan. Which vent fan performs the best?

 No one likes sweaty balls or tatas. No one. If you don't take the right steps to insulate and put a coat of elastomeric paint on your roof when you convert your Skoolie then you will soon find yourself trying to figure out how to cool your bus conversion down. But, even with proper insulation and a UV reflecting paint on your roof, you may find yourself in certain climates that are just hot no matter what and the need to cool your Skoolie down is a must.

In this article I'll cover the two most common vent fans installed and which one isn't so fantastic (spoiler alert!) from my experience and others. It should be mentioned that I bought both of these vent fans and was not asked by either company to write this review. It's my opinion and other people's opinions and experiences could be entirely different than mine. Insert grain of salt here.

Fan Tastic Vent Fan Trash

Fan-Tastic Fan vs. Maxx Air

I currently own a short, 5 window school bus that I've converted into an RV, tiny home on wheels, escape pod or whatever your preferred term is. I spend most of my time in the hot and dry desert climate of Moab, UT and the cool and sometimes humid Oakridge, OR of the Pacific Northwest (or Cascadia). My skoolie has a bathroom with a shower and a queen size bed that is always setup as a bed. I decided to place two fans in my bus conversion, one in the bathroom for shower steam and the unearthly morning after pub food and cider smell, and the other fan above the bed for staying cool at night in the summers as well as to keep the sh!t lion (cat) and dog comfortable when I'm out tromping through the woods.

Because I was planning to install two fans, I decided to order one Fantastic Fan and one Maxx Air fan. I ordered comparable models from each company that were similar in features and price. Here's a feature and price breakdown of each.

Fan-Tastic Vent 803550 Series ($270 as of 8/1/2019)

  • 3 fan blade speeds; Reversible air flow
  • Manual and electric lift dome
  • Built-in thermostat
  • Rain sensor that automatically closes when the dome gets wet

Maxx Air Fan Plus 4500K Series ($239 as of 8/1/2019)

  • 10 fan blade speeds; Reversible air flow
  • Manual and electric lift dome
  • Built-in thermostat with quick "Auto" one press button to open and pull air out at 78 degrees
  • Rain sensor that automatically closes when the dome gets wet
  • Remote control

I tested both fans for a total of 1 year and 10 months in both Utah and Oregon and during all seasons in each state. The MaxxAir was installed in the bathroom and the Fan-Tastic vent fan above the bed.

The results?

If I could football kick the Fan-Tastic vent fan into an active volcano without looking like Charlie Brown, then I'd be doing so right now. Here's my beef.

My first duly noted complaint was how loud the Fan-Tastic fan was when turned on even to the lowest of three settings. My partner Heidi describes the sound as "a jet engine over my head". The next  complaint came after roughly three months of using both fans, I was awoke one night to a pterodactyl in the bus. Or so I thought in my sleepy, White Claw, comma state. The Fan-Tastic vent fan was squealing above our heads. It sounded like a failing bearing similar to when you start your car and have a squealing belt. I did pull the fan blades off and cleaned everything really well and then tried to add a little grease to help but it only lasted a few weeks before the pterodactyl came back to dive bomb my dreams.

The last straw for me was the ghost water leak. Now, I'm no newb when it comes to using caulking and preventing water from entering a home as I grew up working with my father and remodeling homes with his construction business for 15+ years. In fact, when it came to my bus conversion, I went perhaps overboard as I didn't want all my hard work done to the interior to be ruined by a little roof leak that could've been prevented. I have learned from experience with my first bus that silicone is not your friend on a bus roof. Avoid silicone on your roof at all costs if you can.

For each fan I installed I used butyl tape under the lip and self leveling lap sealant on all screws and the edges of the fan. Same methods used on both fans but the Fan-Tastic fan had a ghost leak that I couldn't ever locate but I noticed that the small drip would get in when driving during rain storms as opposed to just parked and raining. In checking the gasket around the vent where it opens and closes I couldn't see any areas of water penetration so alas I'm stumped on how the water was getting in but it wasn't something I was willing to live with.

I have since replaced the Fan-Tastic fan with another Maxx Air Fan Plus 4500k series and added a Maxx Air Vent Cover to allow airflow during rain which helps the most when I'm cooking in wet weather as I can crack a window in the kitchen, turn the fan on high blowing in and it pushes the hot air from the stove out the cracked kitchen window.

To recap here's the list of complaints I had with the Fan-Tastic Vent Fan:

  • Fan sounds like a jet engine
  • Only three speeds for the fan 
  • Fan bearing squeals like a piglet on a roller coaster
  • Mysterious entry point for water while driving in rain
  • I have to flip four separate switches to get the fan to operate how I prefer
  • No remote which required me to climb on the bed each time I wanted to turn on or off the fan
  • Thermostat is displayed with a cold (blue) to hot (red) colorway so I have to guess that perhaps the third red block in the colorway is 78 degrees
  • It was more expensive with LESS features

Here's what I love about the Maxx Air Fan:

  • Fan is quiet
  • Fan has ten speeds to choose from
  • Controls for the fan are push buttons and I can press one button (Auto) which will open the vent, turn the fan on pulling air out and run until it hits 78 degrees after which it will auto close itself. I also have the option with the remote to change the thermostat temperature to higher or lower before it will turn off and close the dome.
  • The remote makes it easy to turn on and off the fan or open and close the vent from a distance which makes it nice when I'm battening down the hatches to get ready to drive and may be in a hurry.
  • Thermostat is a digital readout on the remote and not only can you adjust what you want the inside temperature to be but it also tells you what the inside temperature currently is.
  • It's less expensive with MORE features

If you're looking for the best way to keep your bus conversion, van conversion or other escape pod cooler with a vent fan, then I would advise to give the Maxx Air Fan Plus 4500k a whirl (pun intended). Below I'll include some links to the fans and products I mentioned earlier for ease of locating.

You may also find this article I wrote on How To Run An Air Conditioner Off Solar Power with the expertise of Garret Towne, President of AM Solar. Is it even possible? You'll be surprised. I definitely was.

Lastly, it's worth mentioning that there are evaporative swamp coolers for RV's worth looking into. They use very little power but a good amount of water. I haven't had any experience with them but discovered them in doing some research.

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Can you run an AC unit off solar power for your Skoolie? You'll be surprised on what we found out in our research.

There's nothing worse then travelling in your escape pod during the summer and spending time in a climate that can get miserably hot without a way to cool down. Even if you've installed a couple of good vent fans and treated your roof with a UV reducing elastomeric paint, you just can't beat the heat without a way to create cool air inside your Skoolie (or other escape pod of choice).

Solar Panels With Skoolie Bus Fair

A short Skoolie at The Bus Fair in Oregon charges off the sun during the event.

A question I commonly get asked is, "How many solar panels do I need to run an air conditioning unit?". For the longest time I used to answer that question by explaining that you would never have enough solar panels or a big enough battery bank that would fit inside a school bus conversion that would be able to run an AC unit. But, in doing some research on this article I tapped on Garret Towne, President of AM Solar to give me the technical details behind why you can't but was shocked by his reply. Here's what Garret had to say:

"When someone mentions that they want to run an air conditioner I tell them they will need at least a 3000VA inverter and 200Ah of lithium battery capacity per one hour of runtime at full power for a 15,000BTU unit.

Solar will be one of a couple charging sources for the rig, but due to limitations in the amount of power radiated from the sun per square foot on planet Earth and the limited size of a skoolie’s roof, you will never be able to park out in the desert and run a 15,000BTU air conditioner 24/7. 

Here are the numbers: 

For simple math, let’s say an air conditioner draws 15A of current at 120V AC. That works out to 1,800W.

If you run it for an hour, that is 1,800Wh or 1,800Wh / 12V = 150Ah. I tell people they need 200Ah because not all lithium batteries can safely discharge their full rated capacity, and because it is likely that there will be other loads running at the same time. I recommend Lithium, because lead-acid batteries have voltage sag and a battery bank large enough to run an air conditioner for a substantial length of time would be impractically heavy.

Also for simple math, let’s say a solar panel produces 3Wh per day per 1W of rated output. This number varies depending on latitude and weather, but 3Wh per day / 1W is a pretty close approximation.

One hour of air conditioner operation would require 1,800Wh divided by 3Wh/day per 1W = 600W of solar left in the sun all day.

A 170W solar panel takes up about 11 square feet. 600W / 170W x 11sf = 39 square feet.

To run the 15,000BTU air conditioner for 24 hours with no charging sources, you would need 3600Ah – 4800Ah of lithium capacity.

To run the 15,000BTU air conditioner, continuously, from solar, you would need a battery bank large enough to serve as an energy buffer from peak production hours through the night, roughly 3000Ah and a 14,400W solar array. The solar array would take up 936 square feet. 

If your roof mount array was 8 feet wide, your skoolie would need to be at least 117 feet long.

In summary:

You can run an air conditioner for short periods of time, but you will need to plan to hook up to shore power, run a generator, or use an alternator charge to help your solar array top off your batteries in between uses. Of the rigs I’ve dealt with where air conditioning is a major concern, they have had between 400Ah and 1800Ah of lithium battery capacity.

It's also worth mentioning that in testing we've seen impressive results from alternator charging systems. One we tested got 129A at idle. That’s the equivalent of roughly 2000W of solar panels."

I had to read over that a few times before the numbers started to click for me and a visual image started to form. While it IS actually possible to run an AC off of solar panels and a battery bank, it's not for very long due to the lack of square footage needed for panels and batteries to make it happen.

Hypothetically if you had a 117 foot long bus and a big enough lithium battery bank, equipment pricing alone for a system with a 3000VA inverter kit, 3600Ah lithium battery kit, and 80x 170W solar panels, along with other system essentials would work to roughly $90,000. Not really the coin that many of us have on hand. Unless you're friends with Oprah? "And you get solar! And you get solar! And you get solar!"

Broccoli Bus Battery Bank

An impressive and massive power bank by Broccoli Bus as displayed at The Bus Fair

An alternative to an AC unit that I just learned about the other day is an RV swamp cooler or evaporated cooler made by TurboKool which uses very little energy. Granted it would only work in dry climates due to how swamp coolers are designed and a little looking into I learned it uses on average 10 - 15 gallons of water per day. My bus only has a 30 gallon fresh water tank so for me that's not really an option unless I knew I was close to a fresh water tap that I could top off each day.

If you're looking to invest in solar for your bus conversion, van conversion or other escape pod, the crew at AM Solar (an employee owned company) are a great resource to reach out to with questions. They also now offer solar kits for Skoolies that are designed around three types of needs. Weekend warriors, those who want a little more juice and be out a little longer and those looking to full time.

AM Solar Skoolie Kits

Short Bus Kit

340W 200A 220AhAGM 500VA

Learn More

Adventure Bus

680W 200A 400AhAGM 2000VA

Learn More

Full Timing Bus

860W 200A 600AhLi 3000VA

Learn More

If you're interested to read more articles that Garret has contributed you can do so here:

Articles By Garret Towne

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Your Complete Guide To Life On The Road In A Van

John and Jayme from Gnomad Home just dropped a great little article on the ins and outs of Vanlife that's worth a read if you're still trying the make that decision on whether a van conversion or bus conversion is best for you.

These two have been living vanlife for quite some time now and the insight they provide in their article is a vault of knowledge for anyone that is completely new to making the lifestyle change.

Here's a quick preview of the topics they cover:

What is Van Life?

  • Why Would You Want to Live in a Van?
  • What Are the Challenges of Vanlife?

How to Live in a Van

  • Converting a Van into a Mobile Living Space
  • Where to Park Your Van at Night
  • Bathrooms, Showers, and Laundry
  • How Much Does Vanlife Cost?
  • Making Money on the Road
  • Getting Mail on the Road
  • Insurance (health, auto, property, etc)
  • Resources and Community on the Road

Check out the full article here.Check out the full article here.