RADIATORS

Radiators For Peterbilt Trucks

The radiator is the primary heat exchanger in a Peterbilt's cooling system — it dissipates the enormous thermal load of a high-output diesel engine through the fins and tubes of its core. A leaking, restricted, or damaged radiator cannot maintain safe coolant temperatures under load, leading to overheating events that can cause head gasket failure, liner cavitation, and in severe cases, catastrophic engine damage. We carry replacement radiators for Peterbilt trucks in aluminum and plastic-tank configurations for common engine and wheelbase combinations.

Frequently asked questions about radiators

How do I know if my Peterbilt radiator needs to be replaced versus repaired?

Minor leaks at the tank-to-core seam or a small puncture in the core can often be repaired by a qualified radiator shop at a fraction of replacement cost, provided the core fin density and tube condition are still adequate. A core that's severely corroded internally, has collapsed tubes from scale buildup, or has sustained physical impact that crushed a significant section of fins typically warrants outright replacement. An internal flow test or boil-out at a radiator shop can determine whether the core's capacity is still sufficient before committing to repair versus replace.

What coolant type should I use in a Peterbilt radiator?

PACCAR MX engines require an OAT (Organic Acid Technology) or HOAT coolant meeting the engine manufacturer's specification — typically a nitrite-free formulation for aluminum cooling system components. Cummins-powered Peterbilts use Fleetguard DCA-treated coolant for cavitation liner protection. Mixing coolant types degrades additive packages and can cause gel formation that blocks the radiator and heater core. Always drain and flush completely before switching coolant types and refill with the correct concentration for your climate.

How often should the cooling system be flushed on a Peterbilt?

Most engine manufacturers recommend a complete cooling system drain and flush every 300,000 miles or 6 years with extended-life OAT coolant, with SCA levels tested and maintained at each PM interval in between. Conventional green coolant systems require more frequent changes — typically every 2 years or 100,000 miles. Neglecting coolant maintenance allows the inhibitor package to deplete, leading to liner pitting on wet-sleeve engines and internal corrosion of aluminum radiator components.

Other parts you might need

Shop charge air coolers for Peterbilt trucks