Proper Air Brake Inspection Using The LABS Test

June 14, 2022

Fleet inspection before any trip is critical to the health and safety of your vehicles and their operators. Arguably one of the most important inspections is that of your air brakes. The good news? Testing air brakes is made simple when you apply the LABS test.


Before your fleet hits the open road, here’s how you can ensure your air brakes are functioning properly. 


Conducting The Four-Step LABS TEST

The LABS test is the best way to remember exactly what to look for when you’re conducting a pre-trip inspection of your air brakes. This acronym should be conducted in the same order as the letters, which include the following steps: 


  1. Leaks: Once the wheels are chocked and you know that the air pressure has built up to between 90 and 125 psi, make sure to leave the vehicle in neutral and cut the engine. Turn the key to the “on” position, release the parking brakes, and then apply steady pressure to the brakes for one minute. If the pressure drops below 3 psi for a tractor or 4 psi for a tractor/trailer combination, your air brakes need to be maintenanced. 
  2. Alarms: Check your alarms to ensure that they alert you should your air brakes experience a drop in air pressure. This can be achieved by engaging your foot brake until a visual or audible alarm indicates a drop in pressure of no more than 60 psi. 
  3. Buttons: Are your parking brakes in working order? You can double-check this by applying and releasing pressure on your foot brakes until the knobs for your parking brakes are forced out. If this doesn’t happen before the pressure reaches 20 psi, the failsafe is not working, and this needs to be taken care of immediately. 
  4. Service brakes: Much like the first test, you will need to grab the wheel chocks and build up the air pressure to around 120 to 125 psi. Then, place the vehicle in low gear, release the clutch, and brake, moving forward at around five miles per hour. Push the clutch and the brake pedal once the vehicle has started moving and pay attention to the wheel. Should the wheel jerk to the side, this could indicate an issue with the brakes. 


This comprehensive test will allow you to catch any braking issues with your fleet before the vehicles are on the road, ensuring that further damage or accidents don’t take place along the way. As long as you make sure to keep your hands on the wheel the entire time, conduct the LABS test before every trip, and keep an eye out for symptoms of a greater issue with the air brakes, you should be able to navigate the roads safely! 


Get Further Fleet Maintenance Support From Action Supply

Action Supply is here to help you with your fleet maintenance needs, regardless of whether you need support with air brakes, lights, or hydraulic oil. Contact us today so we can learn how we can enhance your industrial business. 


By Jayson Matos February 15, 2026
How Smart Product Selection Protects Reliability & Equipment Performance
January 14, 2026
The start of a new year is more than a calendar reset, it’s an opportunity to strengthen the systems that keep your business running efficiently. For industrial, commercial, and maintenance-driven operations, having the right supplies in place at the right time can mean the difference between staying productive or falling behind. Building a smarter supply strategy early in the year helps businesses control costs, reduce downtime, and remain competitive in an increasingly unpredictable supply environment. Here’s how to evaluate your needs, forecast usage, and put reliable systems in place for the year ahead. Why Strategic Supply Planning Matters Reactive purchasing often leads to higher costs, rushed decisions, and inconsistent inventory levels. Without a clear supply plan, businesses risk overordering, stockouts, and delays that impact operations and customer commitments. Strategic supply planning allows organizations to: Improve operational efficiency Reduce emergency purchases and downtime Stabilize pricing through better forecasting Build stronger supplier relationships When supply strategy is aligned with operational goals, purchasing becomes a competitive advantage, not just a necessity. Step 1: Evaluate Your Current Supply Usage The foundation of any effective supply strategy is understanding what you actually use. Reviewing historical purchasing data provides valuable insight into patterns, seasonality, and inefficiencies. Key questions to ask: Which products are used consistently throughout the year? Where do usage spikes or slowdowns occur? Which items frequently require rush orders or last-minute replenishment? Identifying high-use and critical items helps prioritize where planning and standardization will have the greatest impact. Step 2: Forecast Demand with Operational Input Accurate forecasting requires collaboration across departments. Operations, maintenance, and procurement teams all play a role in anticipating demand. Consider factors such as: Planned maintenance schedules Production volume expectations Seasonal workload fluctuations Equipment upgrades or expansions By incorporating operational insight into forecasting, businesses can better align inventory levels with real-world needs, reducing both excess stock and shortages. Step 3: Standardize Products and Vendors Standardization simplifies purchasing, improves consistency, and often reduces costs. Evaluating opportunities to standardize frequently used supplies—such as safety products, fasteners, tools, or consumables—can streamline procurement and inventory management. Working with a trusted supplier also provides access to product expertise, availability insights, and alternative solutions when supply challenges arise. Step 4: Set Systems in Place Early Establishing purchasing systems early in the year creates stability throughout the months ahead. This may include setting reorder points, implementing blanket orders, or coordinating scheduled deliveries for high-use items. Proactive systems reduce the need for emergency purchases and allow teams to focus on operations rather than constant supply management. Step 5: Build a Supply Partner, Not Just a Vendor A strong supply strategy goes beyond transactions. Partnering with a knowledgeable supplier adds value through product recommendations, inventory support, and responsiveness when challenges arise. The right supply partner understands your business, anticipates needs, and helps you adapt as conditions change throughout the year. How Action Supply Supports Smarter Supply Planning Action Supply works with businesses to develop supply strategies that support efficiency, reliability, and long-term success. By helping customers evaluate usage, identify opportunities for standardization, and implement dependable supply systems, Action Supply helps operations stay prepared, not reactive. Whether planning for routine maintenance, large-scale projects, or day-to-day operations, Action Supply provides the products and support businesses need to stay competitive all year. FAQs Why is supply planning important at the start of the year? Early planning helps businesses forecast demand, stabilize costs, and reduce disruptions caused by shortages or emergency purchases. How can businesses improve inventory efficiency? Evaluating usage data, forecasting demand, standardizing products, and working with a reliable supplier are key steps toward more efficient inventory management. What should a supply strategy include? A strong supply strategy includes usage evaluation, demand forecasting, product standardization, purchasing systems, and a trusted supply partner.
December 16, 2025
Follow these proactive steps to help extend equipment life, maintain performance, and avoid emergency repairs during the coldest months of the year.