How to Adjust and Maintain Your Automatic Slack Adjuster

The automatic slack adjuster is a crucial component in the braking system of commercial vehicles. It ensures that the brakes are properly adjusted, allowing for safe and efficient operation. In this article, we will guide you through the process of adjusting and maintaining your automatic slack adjuster to keep your brakes in optimal condition.

Before we dive into the steps, let’s first understand the two different types of slack adjusters commonly found in commercial vehicles. The Haldex Automatic Slack Adjuster HAL-40010212 (28 Spline, 6″) and HAL-40010211 (28 Spline, 5-1/2″) are among the most popular variations. These reliable and durable slack adjusters are known for their performance and functionality.

Now, let’s get to the steps to adjust your automatic slack adjuster:

Step 1: Safety First
Ensure that your vehicle is securely parked and the parking brake is engaged. Safety should always be your top priority when working on any part of your vehicle.

Step 2: Access the Slack Adjuster
Locate the automatic slack adjusters on each wheel. They are usually found on the rear axle of the vehicle. Depending on the type of vehicle, you may need to remove the wheel to access the adjuster.

Step 3: Determine Adjustment Direction
Take note of the direction in which the adjuster needs to be turned to tighten or loosen the brake. This information can usually be found in your vehicle’s manual or by referring to the manufacturer’s instructions.

Step 4: Adjust the Slack
Using an appropriate tool, such as a slack adjuster wrench or ratchet, turn the adjuster in the required direction. Be cautious not to over-tighten or loosen the adjuster beyond the recommended specifications.

Step 5: Check the Brake Adjustment
Once you have made the necessary adjustments, it’s important to check the brake adjustment. To do this, pull the slack adjuster arm away from the brake chamber and release it. It should return to its original position, indicating that the brakes are properly adjusted.

Now that you’ve learned how to adjust your automatic slack adjuster, let’s delve into some tips for its maintenance:

Regular Inspection: It’s essential to inspect your slack adjuster regularly for signs of wear, corrosion, or damage. Look out for loose or missing components, as well as any abnormalities in the braking system.

Lubrication: Apply a high-quality lubricant to the moving parts of the slack adjuster to ensure smooth operation. Be cautious not to apply excessive lubricant as it may attract dirt and debris, leading to potential issues.

Cleaning: Clean the slack adjuster regularly, removing any accumulated dirt or debris. This will help prevent any obstructions or hindrances to its functionality.

Professional Assistance: If you are unsure about adjusting or maintaining your slack adjuster, it’s always best to seek professional assistance. Experienced mechanics will have the expertise and knowledge to ensure the proper functioning of your braking system.

In conclusion, the automatic slack adjuster plays a crucial role in maintaining safe and efficient braking in commercial vehicles. By following these steps for adjustment and maintenance, you can ensure the optimal performance of your slack adjuster. Remember to prioritize safety and seek professional help whenever necessary.

For all your truck and trailer needs, be sure to visit With a wide range of options and competitive prices, they are the go-to destination for buying or selling any commercial vehicle or equipment. And if you require financing, look no further than They specialize in providing affordable financing solutions for semi trucks, trailers, and equipment.

Click Here For Trucking Industry Lead Lists

Place Your Ad Too. It will only take a minute!

Register Right Here to place your ads Right Now. All of your ads will be shared across HUNDREDS of Trucking Industry Related Facebook Groups filled with Targeted Buyers and Sellers. Millions of people will see your ads now. No contracts or commitments with a money back guarantee. You have nothing to lose.