Coolant leak detection & repair
Coolant can disappear quietly: the reservoir level falls but there is no puddle beneath the vehicle.
Symptoms
- Coolant level in the tank drops with no puddle under the car.
What's included
- Causes can be external—the radiator, hoses, pump, reservoir or heater core—or internal, when fluid enters the cylinders or oil through a blown cylinder-head gasket. We pressure-test the system with a special pump, revealing even a small leak that evaporates immediately on a running engine. We also test the coolant for exhaust gases; this distinguishes a straightforward repair from a serious one. The result identifies what is leaking and why the level fell.
Additional checks
- Condition of the radiator, hoses, pump, reservoir and heater core
- Coolant entering the cylinders or engine oil
Why it matters
A small leak evaporates instantly on a running engine, so the system is pressure-tested with a dedicated pump. A test for exhaust gases in the coolant shows whether the leak is internal, through the head gasket.
More details
Coolant disappears quietly: the level in the tank drops, but there's no puddle under the car. The causes can be external — the radiator, hoses, water pump, expansion tank, heater core — or internal, when the fluid gets into the cylinders or the oil through a blown head gasket. We pressure-test the system with a special pump: this forces even a small leak to show itself, one that would evaporate instantly on a running engine. We separately run a test for exhaust gases in the coolant — this is exactly what tells a cheap repair apart from a serious one. Based on the results, you know exactly what's leaking and why the level was dropping.
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