Common Issues With Heavy-Duty Truck AC Systems And How To Diagnose Them

Heavy-Duty Truck AC Systems Common Issues

During those hot summer months, truck drivers will often depend on the AC to keep them cool and to avoid fatigue and heat-related problems. When temperatures start to drop, they turn the AC up to keep them toasty. These are essential features of a truck that may not affect its performance but can have an impact on the driver. Many issues can affect a heavy-duty truck’s AC system, and we’ll discuss some of them in this post. 

What Causes AC Breakdowns

The AC system can generate heat or blow cold air into the truck, allowing the driver to adjust the temperature of the interior. Unfortunately, sometimes truck drivers may turn the AC on, only to find that it no longer works effectively. It could be that the AC is not providing enough airflow or perhaps it does not reach the desired temperatures. 

In this section, our focus is to provide details of common reasons why AC systems tend to break down and experience troubles.

  • Refrigerant That Is Leaking: A relatively common reason why the AC in a heavy-duty truck does not work properly is due to leaking refrigerant. This is particularly the case when the AC does not cool down the interior of the truck. When the AC is turned on, there is a compressor that needs to cool the refrigerant that is added to the system. In addition to cooling down the refrigerant, the compressor also helps to ensure there is a constant circulation of air. If the refrigerant leaks, then it means there may not be enough of this compound for the compressor to cool. Thus, the air that is blown into the truck through the AC system would not be cool. Various things can cause a leakage of refrigerant, such as holes in the tubes that are responsible for carrying the liquid to the compressor. 
  • Compressor Is Overworked: The compressor that is part of the AC system in a heavy-duty truck only processes gasses. Sometimes, contamination happens, which is when dirt, other liquids, and air start to accumulate in the compressor and surrounding areas. If these contaminants build up in the compressor, the entire AC system needs to work much harder to cool down or heat the vehicle. In the long run, this can cause damage to different components of the air conditioning system and make it less efficient in its functionality. 
  • Condenser That’s Clogged: When gasses enter the condenser, they are converted into a liquid form. These liquids help to expel heat and play an important role in how the AC system functions. Grime eventually starts to form on the coils that the condenser unit uses, along with dirt. These layers accumulate and can eventually become so thick that it causes the condenser to become clogged. If the problem is not addressed, blockages in the condenser can happen, potentially causing damage to the system and reducing its ability to blow cool or heated air into the truck. 

Common Fixes For Heavy Duty Truck AC Problems

We’ve looked at a few common causes that can lead to problems with the AC in a heavy-duty truck. We will now take a closer look at ways in which you can potentially prevent serious damage to the AC system by taking precautionary steps. 

  • Regularly Check For Leaks: Some many hoses and pipes connect various parts of the AC system. It’s possible that over time, these components can be damaged and develop tears or leaks. Leakages are quite commonly associated with AC troubles, so it’s something that you should check for regularly. If you notice even small holes in pipes that are used in your AC system, then you should consider getting them replaced. These small holes will develop over time and become more significant problems. 
  • Take Care Of Contaminations: Mold, mildew, dirt, and several other elements can enter parts of your AC system and cause problems, such as poor efficiency or blockages. Regularly checking for debris accumulation in your AC system is a good idea and should be part of your maintenance strategy. Take a look at the air filters in the system and inspect the evaporator coils. These are common areas where debris can build up and affect the performance of your AC. If there is a more significant buildup, you may need to take the truck to a repair shop for professional cleaning. 
  • Recharge The Refrigerant: Leakages of the refrigerant used to cool down are particularly common problems behind AC system faults. This is why it’s important to regularly recharge the system to ensure there’s a sufficient amount of this component available in the AC. You do need to be careful about the specific refrigerant you use. Make sure you look through the manufacturer manual that came with the truck or look up the model number of the heavy-duty truck on the internet. Choosing the wrong refrigerant could cause further issues to develop in the AC system. You should plug the refrigerant into the area underneath the low-pressure valve, then allow it some time to properly recharge. 

While these tasks seem simple, they sometimes require inspection by a professional. If you take a look at all the signs of AC troubles and still experience faults with this system in a heavy-duty truck, then take it for a preventive maintenance service at a local repair shop. The experts at the repair shop are equipped with the knowledge needed to effectively locate a fault in the AC system and address it before it becomes worse. 


Problems with the AC in heavy-duty trucks can become quite problematic, so you want to ensure you get them fixed at a trustworthy service supplier. Follow the tips and diagnostics we discussed, and if you do run into AC troubles, give Bus & Truck of Chicago a call to get them fixed by the professionals in the area. We also specialize in wheel alignment, suspension services, and more to help your trucks always run optimally. 


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