Knowing how to replace the brake pads and the engine oil is among the basics all truckers should be knowledgeable about, but when you want to save money on mechanics, knowing how to replace the air dryer in your Volvo VNL. Here are the steps you should take to make sure you’re doing a good job changing your air dryer:

Items needed:

• A replacement air dryer compatible with your Volvo VNL
• A set of wrenches
• Ratchet and socket set
• Screwdriver
• Torque wrench
• Thread sealant
• Safety gloves and goggles

Step 1: Locate the Air Dryer

The air dryer is typically located near the rear of the cab, attached to the truck’s air brake system. It is often mounted on the frame rail or near the air tanks. You can also consult your truck’s manual for more precise guidance.

Step 2: Depressurize the Air System

After you remove the air dryer, it is important to release the pressure from the air system. You do this by turning off the truck’s engine and draining the air tanks. It’s also a good idea to open the manual drain valves on the tanks to make sure all air is fully released.

Step 3: Disconnect the Electrical Connections

Disconnect the electrical wiring harness attached to the air dryer. The wiring powers the heater and purge valve, so it’s essential to remove it safely. Mark the wires or take pictures so you can easily reconnect them later.

Step 4: Remove the Air Lines

Use your wrench to loosen and remove the air lines connected to the air dryer. Be cautious, as these lines can still have residual pressure. You might want to wear gloves for protection.

Step 5: Unbolt the Air Dryer

With the air lines and electrical connections detached, use your ratchet and wrench to unbolt the air dryer from its mounting bracket. Remove the air dryer and set it aside.

Step 6: Install the New Air Dryer

Position the new air dryer in place, bolt it securely to the mounting bracket and make sure it is tightened to the manufacturer’s recommended torque specs. Apply thread sealant to the fittings if needed.

Step 7: Reconnect the Air Lines

Reconnect the air lines to the new air dryer. Make sure the connections are tight and properly seated to prevent leaks and double-check each fitting to ensure proper placement.

Step 8: Reconnect the Electrical Connections

Reconnect the electrical wiring harness to the new air dryer. If you labeled or took pictures of the connections earlier, use them to ensure each wire is connected correctly.

Step 9: Test the System

Once everything is connected, start the truck’s engine and allow the air system to pressurize. Listen for any air leaks and ensure the air dryer is functioning properly. Check the purge cycle to confirm it is operating correctly.

Important!

After you finish all the steps listed above, make sure to perform a final inspection.  Check all connections, bolts, and fittings to ensure they are secure and verify that there are no leaks or electrical issues. Take your truck for a quick ride to confirm the air brake system is working efficiently. Keep hauling!