truck trailer brakes

A guide to adjusting your tractor-trailer brakes

When it comes to ensuring the safety and reliability of your tractor-trailer, maintaining the brakes is a critical task. That’s why one of the key maintenance tasks for truck drivers and owners is adjusting tractor-trailer brakes. Here’s a guide to help you go through the different steps and ensure your brakes are always working at their best.

The importance of brake adjustments

Brakes are responsible for stopping a vehicle, and on a semi-truck, this function is even more crucial due to the weight and size of the vehicle. Semi-truck brakes and tractor-trailer brakes are designed to handle these loads, but over time, they can wear down or become misaligned, which may cause your braking system to become less effective, increasing stopping distances and putting you at greater risk of accidents.

How to adjust your tractor-trailer brakes

Step 1: Check the brake shoes or pads

The first step in adjusting semi-trailer brakes or semi truck trailer brakes is to inspect the brake shoes or pads for wear. If your semi trailer disc brakes or drum brakes are worn down too much, it’s time to replace them. Inspecting the brake shoes is important because worn-out shoes can lead to inefficient braking, putting additional strain on other brake components.

Step 2: Measure the push rod stroke

The push rod is an important part of your tractor trailer brakes. To adjust the brakes, you’ll need to measure the push rod stroke. When you apply the brakes, the push rod extends. For most trucks, the push rod stroke should be between 1 and 2 inches. If it’s outside this range, the brakes are likely out of adjustment and need to be fixed.

Step 3: Adjust the brake drum

Once the push rod stroke is measured, you’ll need to adjust the brake drum. This is typically done by turning the adjustment bolt on the brake assembly. By tightening or loosening the bolt, you can move the shoes closer to the drum or further away to ensure proper braking contact.

If your semi truck has disc brakes, you may need to adjust the calipers instead. Ensuring that the brake pads are evenly spaced from the rotor is key to maintaining effective braking performance.

Step 4: Test the brakes

After adjusting your brakes, it’s important to test them to ensure they are functioning properly. Adjusting semi truck brakes should always be followed by a road test or at least a test on a flat surface to ensure the vehicle stops smoothly. Listen for any unusual noises, such as grinding or squealing, which may indicate further adjustments or replacements are needed.

Common issues with tractor-trailer brakes

There are a few common issues that can occur with tractor-trailer brakes that may require adjustments or repairs. These include:

  • Air leaks: If there’s an air leak in the braking system, the brakes won’t function properly. This can be caused by a loose connection or a cracked hose.
  • Worn brake shoes or pads: As mentioned earlier, worn brake components need to be replaced for the brakes to function effectively.
  • Faulty brake chambers: If the brake chambers are damaged or malfunctioning, it can lead to poor brake performance and require adjustments or replacements.

Regular inspections and adjustments of your semi trailer brakes can prevent these issues from escalating.

Importance of regular brake maintenance

Regular maintenance of your semi truck and trailer brakes is crucial for ensuring safety and optimal performance. Adjusting your tractor trailer brakes every few months, or more frequently depending on usage, can prevent major issues and ensure your vehicle stops effectively when you need it most. Not only does this keep you and other road users safe, but it can also save you money on costly repairs by catching problems early.

Adjusting tractor trailer brakes is a task that every truck driver and owner must prioritize to ensure safe driving. It’s important to regularly inspect, adjust, and replace semi-truck and trailer brake components as needed. 

At TMS TruckMasters, we offer expert brake adjustment services for all types of heavy vehicle, including semi-trucks and trailers. If you need help with adjusting semi truck brakes or any other truck maintenance, don’t hesitate to contact us. Our team is here to keep your vehicle in top condition.