4 Tips For Inspecting A Used Semi Truck Before You Buy It

Posted on: 7 March 2017


If you are interested in buying a used semi truck for your business, you may not be certain about how you should go about selecting the right one. If so, use the following four tips when inspecting each truck.

Inspect The Tread On The Tires

According to federal regulations, the minimum tread depth for a commercial motor vehicle's steer tires is 4/32 of an inch and 2/32 of an inch for all other tires. However, individual states may require a deeper tread. You may want to contact your state's department of transportation to find out the exact requirements.

When checking the tire tread on a semi truck, carefully check the major grooves in the center of each tire, as well as along the wall. One way to do this is to use a sewing gauge, which is used when hemming clothes. It has a slider that allows you to mark the exact measurement. Then, you can see how the tread measures up to the marker.

Look For Signs Of Leaks In The Engines

Another thing you want to do when inspecting a used truck is to look for signs of any leaks. The first place you can look is under the truck after it has been running. If you see pools of water, oil, or fuel, there could be a broken hose or crack in a fluid line. 

Next, check under the hood and look at the engine itself. It should be relatively clean with no noticeable grease or oil marks collected in one area. If you do suspect there is a leak, speak with the representative. The problem could be as simple as a leaking hose that they may repair for you for minimal or no charge.

Check The Color Of The Exhaust

After checking for leaks, have the sales representative fire up the engine so you can examine the color of the exhaust coming from the stacks. You may see a small amount of black smoke when the engine first starts, followed by a light gray color. This means the air and diesel fuel is mixing properly.

However, if the smoke from the stacks remains black, too much fuel is being burned by the engine. Not only could this wear down the engine faster, but the fuel consumption of the truck will be high, leading to higher fuel costs. 

Ask For The Maintenance Logs

After you have physically inspected the truck, ask to see the maintenance logs, which are required by law for commercial vehicles. These logs can give you a good overview of how well the truck was maintained, as well as of any recurring issues over the life of the vehicle.

One thing to look for in the logs is the frequency at which the fluids are changed. For example, if the oil has been changed monthly, the gears and pistons inside the engine are likely running smoothly and will last a while longer.

However, if the oil was only changed a few times a year, there is a possibility that there is sludge inside the engine that could impact the engine's function. If the gears have not been properly lubricated by fresh oil, they could have started to wear down. This could lead to the engine seizing up if the sludge is not flushed from the system.

Using the above inspection tips should help you find a used semi truck that will require minimal or no extra maintenance work. If you still have questions or concerns on making your selection, you may want to speak with a sales representative from a company like Arrow Truck Sales for further advice and information.