All professional drivers should know how to and be performing daily pre-trip and post-trip inspections. Not only are regular inspections required by law in both Canada and the USA, but they are simply a best practice if you want to be a safe operator.
Many drivers, unfortunately, pay little attention to the underside of their vehicles. Since people are in a hurry and may not want to get down and dirty, mechanical defects underneath the truck often go unnoticed until the truck is either seen in a shop or subject to a Level 1 inspection at a scale.
Find a way to make detailed under-truck inspections part of your routine. It will add time, but the more you do it the faster you will get and also the more comfortable you will become with the mechanical workings of your truck. And remember to measure those pushrod travel distances on your drum brakes!