Any time you’re considering buying a used vehicle, you should be sure to carefully inspect it and check for any major problem areas that might impact the vehicle’s performance. For used semi-trucks, this step can be even more critical. Semis undergo extreme strain and put on hundreds of thousands of miles quickly. But what problem areas do you need to double-check to ensure that any used semi you buy is in good condition? Keep reading to find out.
Obviously, the engine is the powerhouse of any semi-truck. It needs to be able to provide relentless, reliable service mile after mile. Before you buy any semi-truck, you should ensure that the engine is thoroughly inspected by a professional. You don’t want to take any chances of having the engine overheat or fail entirely just a few days or weeks into your truck ownership. If buying from a dealer, there should be some kind of warranty to cover engine failure and similar problems for at least six months. For private sales, it’s generally a good idea to pay for an inspection yourself as a way to protect yourself from a lemon—and a semi-sized lemon is much more serious than a sedan-sized one.
Starter mechanisms must be inspected regularly on semis, especially in winter. But regardless of the current temperature outside, if you’re buying a used semi, you should ensure that the starter is tested and inspected. These parts are prone to failure, and you can save yourself some serious hassles down the road if you make sure the starter is functioning properly before you buy.
The U-joint is responsible for transferring power from the transmission to the differentiator. U-joints need to be lubricated to reduce wear and tear, and you might notice a clicking sound or vibrations at higher speeds when they’re about to fail. If you can take the semi-truck on a test drive, be sure to listen for those clicking sounds or vibrations. If you notice it, make sure that the I-joint is replaced before you buy it.
Brakes are one of the biggest parts of your truck’s safety systems. They protect you and everyone on the road with you. Visually inspect the brakes to check the pads for excessive wear and tear. Additionally, check brake fluid levels and inspect the system for brake fluid leaks. For semis, there is a separate, independent brake system that will still allow the driver to stop using the other brakes if just one brake fails, but you should not rely on this; make sure all your brakes are in working order before buying used heavy-duty trucks.