Truck Radiators

Truck Radiators and What You Need to Know About Your Cooling System

All truck radiators need service and every driver should be familiar with the main parts of their vehicles cooling system and how they function together. It is important to be able to quickly address any truck cooling system issues as they become evident. Whether you drive a heavy-duty pickup truck or a commercial 18-wheeler, the following guide should tell you everything you wanted to know about truck radiators.

What is a Truck Radiator and Why is it Important to the Vehicle?

The radiator is one of the most vital components of your truck because it serves the critical purpose of protecting the engine from overheating. Your truck’s engine contains pistons and numerous other moving parts that constantly create friction and heat. Your radiator cools a mixture of water and anti-freeze that is moved through the cooling system by a centrifugal pump commonly referred to as a water pump.

The water pump pushes heated fluid out of the engine’s many chambers and through the radiator where the absorbed heat is released into the surrounding air via a process known as ‘heat exchange’. The cooled fluid is then pumped back through the engine preventing overheating. This cycle occurs continuously for as long as your truck is running.

If the radiator fails to work properly, the engine will overheat, and damage can occur. Some common results from overheating are a blown head gasket, warped head, damaged valves or pistons, a cracked engine block, a blown radiator, and hoses bursting. Note: We’ll discuss common repair and maintenance issues later in this guide, as well as a number of reasons why your engine overheated, to help you learn more and avoid a breakdown.

What are the Differences Between Car and Truck Radiators?

Car and truck radiators are very much the same. The science that cools your car also works very well for your truck. The primary difference between car and truck radiators is their size, capacity, and durability. Truck radiators are designed to accommodate the heavy loads, vibrations, stresses and high miles.

There are two main styles of radiators used in both automobiles and trucks, the cross flow radiator, and the down flow radiator. A cross flow radiator is configured with the coolant tanks on the sides (fender to fender) with fluid running horizontally across the front of the vehicle. The down flow radiator has the tanks on top and bottom where the fluid runs vertically down the front of the vehicle.

Two other types of radiators used mostly on heavy-duty trucks are the low-flow radiator that uses multiple passes of coolant through the radiator and a bolt-on radiator where the tanks are bolted onto a core using a gasket.  Both these types of radiators can be made using either a crossflow or a down flow style. We will discuss all types of radiators in more detail in another article.


Bolt-On Radiator

What Materials are Truck Radiators Made From, and Why is it Important?

Truck radiators must be made with durable materials that can withstand the constant stresses generated by hauling heavy loads over many miles. The main materials used in today’s radiators include copper, brass, aluminum, plastic, and steel. The material used in manufacturing a truck radiator is very important because it determines how efficiently the radiator core will cool the engine and how durable the radiator will be.

In the past, radiators were mostly made of copper, brass and steel. They were assembled by soldering components together or bolted together. Today, however, aluminum radiators with plastic tanks and gaskets have made large inroads into the radiator market for a number of important reasons that we will address in a later article.

What Types of Repairs or Preventative Maintenance are Usually Required?

If your radiator is not working properly then the problem probably stems from one of the following issues:

Leaky Radiator Hoses – When there is a leak in the cooling system, it isn’t always within the radiator itself. A lot of the times, a leak comes from one of the hoses or clamps that connect everything together. Hoses are categorized as a “wear component’ and should be routinely inspected and replaced based on miles, condition and time.

Sticking or Failed Thermostat – If your thermostat fails then the radiator can’t accurately do its job. A thermostat that only partially opens will allow the coolant to move too slowly through the radiator. A thermostat that is stuck shut will stop the flow of coolant and quickly cause overheating, and a thermostat stuck open will not allow your vehicle to warm up properly. You should always be aware of your temperature gauge and what it is telling you.

Air Bubbles in the Cooling System – Air pockets or bubbles can become trapped within the cooling system and cause overheating. Anytime a cooling system has a leak, is flushed, or a part is changed you will need to check for air pockets. If your truck is overheating and other problems have been ruled out check for air pockets and remove any trapped air by “burping” or bleeding the cooling system.

Finding Radiator Core and Tank Leaks – Radiator core and tank leaks can be tough to repair. If you are considering repairing, the best advice, we can give you is to seek out a professional radiator repair facility. Patching a leak is only ok if you are on the road, or you just need some time to get to a repair shop. A patch will normally only delay your needing to address the situation and may cause worse problems and even engine damage.

– Defective Water Pump – A failing water pump is one of the most common causes of overheating and if left unabated, can cause irreparable damage. If you are overheating and don’t know why have your water pump and cooling system checked at a radiator shop or truck mechanic. At times, a defective water pump can be hard to diagnose.

Cooling System Fan – When your truck is moving, the airflow coming in from the grill or vents helps to keep your radiator air-cooled. However, high outside air temperature or traffic can reduce the cooling effect of the outside air. The fan will then be needed to pull the proper amount of air through the radiator, helping to cool the fluid. If you experience vehicle overheating at idle or in traffic, there may be a problem with the fan or blockage in front of the radiator or internally.

Obstructions to the Cooling System – Sludge, cottonwood fluff, dirt, debris or damage to the radiator itself can cause obstructions within the cooling system.  Any obstructions that impedes air flow or lowers heat dissipation can lead to truck overheating and a breakdown. Truck inspections must be performed periodically, to make sure the cooling system is clean and unobstructed so that you can prevent truck radiator overheating.

Checking For Leaks – You will need to check the hoses and radiator regularly to confirm that there are no early signs of leaking.  A pressure test can help uncover any high-pressure leaks that may go unnoticed with just a visual check.

– Adding Radiator Coolant – Make sure you keep the coolant topped up to the proper level to avoid overheating or air pockets. A single air pocket can notably decrease the efficiency of your cooling system causing hot spots and engine damage. Never open your cooling system while hot and only fill to the cool level.

Radiator Cap – The radiator cap is an important part of your cooling system and is needed to maintain the proper pressures within your system. Your cap can prevent overheating, and engine damage and must hold and then release pressures at the proper time. Use a pressure gauge to check your radiator cap and make sure it holds and then releases at the proper point.

Adjusting Antifreeze Mixture – You should use a mixture of 50% water and 50% antifreeze in your cooling system unless the temperature is below -34°. Too much antifreeze mixed with water can cause gelling, poor circulation and overheating. Plain water does not have the proper additives, and 100% antifreeze is the worst.

Avoid using the Wrong Radiator Fluid – Your cooling system needs a specific blend of additives to protect it based on the different metals used in your system. Do not mix colors and use the correct mix of water and antifreeze. If you are not sure, stop what you are doing and find out before mixing fluids. Using the proper antifreeze can help avoid a lot of unnecessary repairs.

Additional Informational Resources

If you’d like to learn more about truck radiators the following resources will help: