Peterbilt 357/378 Charge Air Coolers

Frequently Asked Questions About Peterbilt 357/378 Charge Air Coolers

What does a charge air cooler do on my Peterbilt 357 or 378?

A charge air cooler, also called an intercooler, cools the compressed air coming from the turbocharger before it enters the engine. Cooler, denser air improves combustion efficiency, helps the engine produce more power, and reduces strain on internal components. If your truck is running hot, losing power, or throwing related fault codes, a failing charge air cooler is often the cause.

How do I know if my charge air cooler needs to be replaced?

Common signs include visible cracks, oil residue or leaks around the fins or end tanks, bent or crushed fins that restrict airflow, loss of engine power, increased fuel consumption, or coolant/boost related warning lights. A shop can also perform a pressure test to confirm a leak that isn't visible during a simple inspection.

Will a replacement charge air cooler fit my specific Peterbilt 357 or 378 without modification?

Charge air coolers can vary by cab configuration, engine option, and model year, so it's important to match the part to your truck's specifications rather than assuming a universal fit. Check listed dimensions, mounting points, and inlet/outlet sizing against your OEM unit, and reach out to our team with your VIN or engine details if you're unsure before ordering.

Are these charge air coolers OEM or aftermarket, and what's the difference in quality?

Our selection includes both OEM and quality aftermarket options. OEM units are built to match factory specifications exactly, while aftermarket coolers are manufactured to fit and perform comparably, often at a lower cost. Aftermarket doesn't mean lower quality, but construction materials and tank designs can vary between brands, so check the product details and core construction if you have a preference.

What's involved in installing a new charge air cooler, and can I do it myself?

Installation typically involves removing the front grille or hood components, disconnecting the ducting and mounting hardware, and swapping the old unit for the new one before resealing all connections. It's a manageable job for someone comfortable with diesel engine work, but proper torque on clamps and fittings is important to prevent boost leaks. If you're not experienced with this type of repair, having a qualified diesel technician handle the install is a safer bet.