Aluminium vs Copper Radiators: Which Core for Your Excavator?

📅 Published: August 24, 2026✍️ By CN Machinery

Every used excavator that crosses a border eventually meets a radiator question: the core is leaking, the fins are packed with dust, and the local shop wants to know whether it is copper or aluminium before they will touch it. The answer decides whether the fix is a two-hour solder job or a new core order. This guide compares the two on heat transfer, weight, repairability and price — and how to check your own machine in five minutes.

1. What Actually Differs Between Copper and Aluminium

Both metals move engine heat into the air through tubes and fins. The differences that matter in the field:

Property	Copper-brass core	Aluminium core
Thermal conductivity	Copper ≈ 401 W/(m·K)	Aluminium ≈ 237 W/(m·K)
Weight	Roughly 1.5–2× an aluminium core of equal capacity	Light — a major saving on the front of a machine
Repair	Soldered or re-cored at a local radiator shop	Brazed as one assembly — replaced, not repaired
Cost	Higher material and labour cost	Cheaper to mass-produce — standard on modern machines
Typical machines	1990s and older builds (Cat 320B era and before)	Machines from the 2000s on — the factory standard
Usual failure modes	Solder joint cracks, tube corrosion	Fin damage, tank seam leaks, tube blockages

The conductivity gap is real but smaller than it looks on paper: a well-designed aluminium core with dense fins rejects heat almost as well, because fin surface area — not the metal alone — does most of the work. What you feel in the field is the weight, the repair story and the price.

2. Which Machines Run Which Core

Caterpillar. The 3406B and 3406C engines used jacket-water aftercooling; from the 3406E onward Cat moved the heavy-bore range to air-to-air aftercooling with an aluminium core, and the C-series kept it. An excavator built in the 1990s — a Cat 320B, an early Komatsu PC200-5/6, a Hitachi EX200 — very likely still has its original copper-brass radiator; a machine built after 2005 almost certainly runs aluminium, often with plastic side tanks.

Komatsu. The PC200-8 — the highest-volume excavator on the used market across Africa, the Middle East and Southeast Asia — uses an aluminium air-to-air aftercooler core in the cooling package, OEM number 20Y-03-41131, which also fits PC200LC-8, PC210-8K, PC210LC-8K, PC210NLC-8K and PC230NHD-8K. Aftermarket aluminium cores list around USD 715 at US online retailers (FridayParts, checked August 2026). The modern cooling package is aluminium end to end.

No paperwork handy? Check in five minutes: copper-brass cores are reddish-brown and heavy when you lift a corner; aluminium cores are silver-grey and light, many with black plastic side tanks. Twenty years in the sun and still copper-coloured — it is copper. Silver — aluminium.

3. Repair vs Replace: The Cost Logic

The material decides the repair route — and the bill.

Copper-brass: a leaking tube or cracked joint can be soldered in an afternoon, and a badly corroded core can be re-cored with new tubes and fins. In markets with strong local radiator shops — common across West Africa and the Gulf — a copper radiator is a repair item, not a replacement item.

Aluminium: modern cores are brazed as one assembly, so a leaking tank seam or holed tube is a replacement job. TIG welding is possible but rarely worth it on a 20-ton machine, and a plastic-tank unit is not repairable at all.

The numbers put it in perspective. For a 20-ton excavator, an aftermarket aluminium radiator is roughly USD 250–600; dealer OEM runs USD 900–1,800. Catching a small leak early costs USD 200–800; ignoring it until the engine overheats can destroy the head gasket, pistons and liners in one session — USD 2,500–6,500 in parts alone. We covered the stages in our radiator failure signs guide; the short version is that a radiator decision delayed is an engine decision made.

4. What to Specify When You Order

The order has to match the machine, not just the metal. Five things to have ready:

• Machine model and serial number — the serial decides the core's dimensions, port positions and mounting.
• The number stamped on the old core — OEM part number if it survived, otherwise the aftermarket number it replaced.
• Core vs complete assembly — tanks, mounts and hoses as one unit, or a bare core.
• Port side and hose routing — swapping to a unit with ports on the wrong side means new hoses and brackets.
• Pressure cap rating — match the original specification; an over-rated cap can burst an old core.

And one practical question before you order: who will repair it when it leaks again? If no one within a day's drive can weld aluminium, a copper core may be the lower-risk choice even if it costs more — same logic as our radiator replacement guide.

At CN Machinery we source radiators, aftercoolers and oil coolers for Cat, Komatsu, Hitachi, Doosan and Hyundai machines — aluminium and copper-brass. Send your machine model, serial number and a photo of the old core's number plate; we confirm fitment and quote within 24 hours.

FAQ

Q: Which is better for an excavator: an aluminium or a copper radiator core?
A: For a modern machine, aluminium — it is lighter, cheaper and the standard fitment from the factory. Copper-brass conducts heat better (about 401 vs 237 W/m·K) and can be soldered locally, which matters on old machines where no one can TIG-weld aluminium.

Q: How do I know whether my excavator has a copper or an aluminium radiator core?
A: Look at the tank and fins: copper-brass is reddish-brown and noticeably heavy; aluminium is silver-grey and light, many with plastic side tanks. A 1990s build or older (Cat 320B era and before) — copper is likely; from the 2000s on — almost always aluminium.

Q: Can an aluminium radiator core be repaired when it leaks?
A: Generally no. Aluminium cores are brazed as one assembly, so a leaking or damaged core is replaced, not repaired. Copper-brass cores can be soldered or re-cored at a local radiator shop — that is why old copper radiators are still preferred in markets where repair skills are common and import lead times are long.

Q: How much does an excavator radiator cost, aluminium vs copper?
A: For a 20-ton excavator, an aftermarket aluminium radiator runs roughly USD 250–600 and a dealer OEM unit USD 900–1,800 (checked 2026). Copper-brass equivalents are scarce new — they are usually re-cored or rebuilt locally. Send your machine model, serial and the number on your old core and we quote a confirmed fitment within 24 hours.