What is the Radiator all about?

The radiator is the central heat exchanger of your vehicle’s cooling system. As your engine runs, it generates immense heat that could easily melt its own internal components if left unchecked. The radiator solves this by acting as a cooling grid: hot coolant flows from the engine into the radiator’s aluminum or brass tubes, where air—forced in by the cooling fan or the car’s movement—strips the heat away before the liquid is pumped back into the engine.

What common symptoms indicate you may need to replace the Radiator?

The "H" Zone: Your temperature gauge is consistently sitting in the red or significantly higher than its usual midway point.

Colorful Puddles: You notice bright green, pink, or orange fluid (coolant) pooling under the front of your car.

Sweet Smells: A distinct, syrup-like scent coming from the engine bay, which is the smell of boiling ethylene glycol.

Steam: Visible vapor escaping from the front of the car, often indicating a pressurized leak or a "blown" radiator tank.

Discolored Coolant: If the fluid in your reservoir looks rusty or like "milky coffee," the radiator is likely corroded or clogged internally.

Common causes

Cracked Plastic Tanks

Most modern radiators use plastic end-tanks crimped to an aluminum core. Over years of extreme heat cycles, this plastic becomes brittle and eventually cracks.

Internal Clogging

If the coolant isn't changed regularly (every 40k–65k km), rust and scale build up inside the narrow tubes, "choking" the flow.

External Debris

Stones from gravel roads or road debris can puncture the delicate aluminum fins, leading to a high-pressure leak.

Corrosion

Using tap water instead of distilled water in South Africa leads to mineral buildup that eats away at the metal from the inside out.

How it's done:

Diagnosis: The mechanic performs a pressure test to confirm the leak is in the radiator and not a simple hose or water pump issue.

Draining: The old, contaminated coolant is safely drained and captured for disposal.

Removal: Radiator hoses, cooling fan assemblies, and mounting brackets are disconnected so the old unit can be lifted out.

Replacement: A new radiator is installed. A professional will almost always recommend replacing the thermostat and radiator cap at the same time to ensure the whole system is "reset."

Refill and Bleed: The system is filled with a fresh 50/50 mixture of coolant and distilled water. The mechanic then "bleeds" the system to remove any air pockets that could cause "hot spots."

Verification: The engine is run until the cooling fan kicks in to confirm the new unit is holding pressure and regulating temperature perfectly.

Keep in mind:

When replacing the radiator, it is best also to replace the radiator cap and thermostat.

After your radiator is replaced, it is best to check it for leaks to ensure that everything is in working order.

When the radiator is replaced, the entire cooling system should be checked, especially the radiator hoses.

Inspect the radiator for leaks.

Pressure test cooling system.

Remove and replace the radiator.

Fill the radiator with the proper mixture of 50/50 coolant.

Recheck for leaks.

The car is overheating.

Coolant (red, yellow, green fluid) is leaking.

How important is this service?

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