“What should I be looking at when inspecting a bus?”

This is a common question I hear. Someone found a bus online and wants to go check it out, but isn’t sure how to judge the condition and value. To be fair much of the answer is going to depend on the type of bus and the intended use. Some things are universal, so we can start with those.

Tires are expensive. If your bus has worn (or more likely, old) tires, that can set you back a couple thousand dollars in replacements! You can check the tread depth with your finger, but school bus tires almost never actually wear out. They simply get old, turn hard, and dry rot. A good rule of thumb is that tires should last about 7 years and will become increasingly more likely to blow out after that. You can check the age of the tire by looking for the date code stamped on the sidewall, it’s a 4 digit code that’s part of the DOT stamp area. The first 2 digits are the week of the year, the second two are the year. For example, a date code of 0118 would mean the tire was manufactured the first week of 2018. If you’re buying from a bus broker, you can try to haggle to get newer tires swapped from another bus in their inventory.


Oil leaks seem obvious, but the reality is, they all leak a little bit. Some more than others, but it can be hard to determine in a visit. You shouldn’t be able to watch a drip happening, but a little mark on the ground isn’t the end of the world. More importantly, check the actual fluid levels. Big diesel motors hold a lot of oil (18 quarts or more!), and the full range on the dip stick may cover an entire gallon from bottom to top. Find out how long it’s been since the last oil change and you can estimate how much it might be losing. Don’t be too alarmed if the oil is dark, diesel oil stops being clear very quickly.  Transmissions are much less likely to leak in a meaningful way, but the color and smell of the fluid can give you an indication of how well it’s been cared for. If the fluid is dark of smells burnt, the transmission may be long overdue for a service or possibly even overheating. Transmissions don’t last very long if you get them hot!


Rust is another thing to look for, but it’s not always easy to do. You can see rust on the body easily enough, but the floor is a different story. Most buses will have a top layer of rubber, a layer of plywood below that, and a layer of steel at the bottom. Moisture that gets past that top layer can be absorbed by the wood and sit on the metal, causing major corrosion that you won’t see until you’ve pulled the old floor completely out! So look carefully underneath the bus for any signs of rust on the floor, it may be much much worse on the other side. You can also walk around feeling for soft spots in the floor, which are a sure sign that there is water in the wood. Look at the walls for signs of water dripping down, as leaky roofs are a primary cause of wet floors, and emergency hatches almost always leak!


Battery age is a good thing to check out. It’s pretty had to test the health of a battery but, outside of abuse, age is a great indicator of its life. A lot of buses use a standard Group 31 battery, which you can regularly get for under $150 each, but they’re almost always in pairs and should always be replaced in pairs! An old battery wired in parallel with a new battery will wear that new one down fast. A good quality battery should last about 5 years. Also, it is possible that you might have more costly batteries such as 4D or 8D, which aren’t hard to get but much more expensive. A NAPA 8D battery will run more than $400 each! Nobody wants their first stop with their new bus to be an $800 battery replacement.


Test Drive

If you’re buying from a private individual or a broker, you’ll want to take a test drive. This usually isn’t possible with an auction, but some things you just can’t tell without making the wheels spin.

If the bus has air brakes, pay attention to how quickly it builds air pressure. If it takes more than 2 minutes for the low air light to go out, there’s surely an air leak or a problem with the compressor. Air brakes will lock the wheels up when they fail (vs not being able to stop as with hydraulic brakes!) which is something you want to avoid happening on the road. The lever should have good travel but air brakes don’t have the same feel as hydraulic ones.

Buses are slow! Don’t be surprised at how long it takes to get up to speed in most buses. They’re designed to move slowly between residential streets at 30mph, and there’s a good chance the bus you’re driving has never gone more then 40mph in its life. You should already know what engine the bus has, if you also know the rpm limit you’ll be able to tell quickly what sort of speeds it will cruise at. Many buses are happy at 55mph, few are happy at 65mph.

Another piece of hitting highway speeds is to check for wobbles. A bus may be perfectly smooth at 40mph and below (where they spend their lives!) but start to shake above 50. Back tires are rarely balanced, tires can go out of round while sitting. It’s pretty common for a tire to go a bit out of shape if it has sat for more than a week or three, but a short drive should warm the up and any temporary warping should disappear within a few minutes on the highway.

The bus engine will probably be pretty loud, but the noises it makes should be smooth and steady. If you’re looking at a model with a turbocharger, it will likely be audible while you drive. A diesel engine should never cough or sputter, and anything newer than 1990 or so shouldn’t smoke visibly after warming up unless you’ve floored it.


Before You Seal The Deal

Always ask about service records! Consider any service they don’t have a record of as being due immediately. Ask about any manuals or other documentation that came with the bus at purchase, and for any added accessories. You may end up searching online or calling the bus manufacturer about them. Don’t be shy about asking for things that came with the bus!

And of course, don’t feel obligated to buy a bus just because you spent a bunch of time looking at it and test driving it. School buses are still mostly a buyer’s market, there are a lot of great buses out there at great prices. Check out our article on where to buy and how much to pay!