Expansion Tanks for Trucks
A truck's expansion tank is an important component of the engine cooling system. The tank accommodates the
expansion of the coolant as the engine heats up and ensures that the cooling system continues to operate at
the correct pressure. The expansion tank also makes it easy to check and top up the coolant level. A properly
functioning expansion tank helps prevent overheating and contributes to reliable engine operation.
At BAS Parts & Tyres, you'll find an extensive range of expansion tanks and related components for trucks
of various makes and models. From complete expansion reservoirs and radiator caps to level sensors,
connections, and mounting hardware.
What Does an Expansion Tank Do?
Coolant expands as it heats up. The expansion tank accommodates this change in volume, keeping the pressure
in the cooling system stable. When the engine cools down, the coolant flows from the expansion tank back into
the cooling system.
Accommodating Expanding Coolant
The expansion tank prevents excess coolant from being lost when the pressure in the cooling system increases.
This helps the system continue to operate efficiently.
Checking the Coolant Level
Thanks to the transparent housing or level markings, it is easy to check whether the coolant level is still
within the specified range.
Part of a Closed Cooling System
The expansion tank works together with the radiator, water pump, thermostat, and radiator cap to keep the
cooling system closed and at the correct pressure.
Which Components Are Associated with an Expansion Tank?
Depending on the truck model, the expansion tank may consist of several parts or be fitted with additional
components.
- Expansion tank or expansion reservoir.
- Radiator cap or expansion tank cap.
- Coolant level sensor.
- Hose connections.
- Bleed connections.
- Mounting brackets and rubber supports.
- Seals and gaskets.
Why Is a Properly Functioning Expansion Tank Important?
A properly functioning expansion tank prevents pressure problems and coolant loss. This keeps the engine at
the correct operating temperature and significantly reduces the risk of overheating.
- Accommodates changes in pressure and volume.
- Prevents coolant loss.
- Helps prevent overheating.
- Supports stable coolant circulation.
- Extends the service life of the cooling system.
Symptoms of a Faulty Expansion Tank
Problems with the expansion tank can cause the cooling system to function poorly. Common symptoms include:
- Coolant leaks around the expansion tank.
- Cracks in the plastic tank.
- A continuously dropping coolant level.
- Engine overheating.
- A faulty or leaking radiator cap.
- A low coolant level warning.
- Air bubbles in the cooling system.
- Discoloration or ageing of the expansion tank.
Common Causes of Failure
Ageing Plastic
Prolonged exposure to heat and pressure can cause the plastic expansion tank to become brittle and eventually
crack.
Faulty Radiator Cap
If the radiator cap does not regulate the system pressure correctly, excessive pressure can develop and
damage the expansion tank.
Coolant Leaks
Worn hoses, connections, or seals can cause leaks, lowering the coolant level and allowing air to enter the
system.
Overheating
A malfunctioning thermostat, water pump, or radiator can increase the pressure in the cooling system and place
additional strain on the expansion tank.
Choosing the Right Expansion Tank
Expansion tanks differ in capacity, shape, connections, sensors, and mounting points. Therefore, always check
the OEM number, part number, or chassis number before ordering a new expansion tank.
BAS Parts & Tyres supplies expansion tanks for brands including:
- DAF
- IVECO
- MAN
- Mercedes-Benz
- Renault Trucks
- Scania
- Volvo Trucks
New and Used Expansion Tanks
New Expansion Tanks
New expansion tanks offer maximum reliability, a long service life, and a perfect fit in accordance with the
manufacturer's specifications.
Used Expansion Tanks
A used original expansion tank can be a cost-effective alternative, provided it is free from cracks, leaks,
and damaged connections.
Order Expansion Tanks at BAS Parts & Tyres
BAS Parts & Tyres offers a wide range of expansion tanks and components for truck cooling systems. Simply
search by OEM number, part number, or chassis number to quickly find the right expansion tank for your truck.
This keeps the cooling system operating optimally and reduces the risk of overheating and engine damage.
Frequently Asked Questions About Expansion Tanks for Trucks
What does an expansion tank do in a truck?
The expansion tank accommodates the expansion of the coolant, keeps the cooling system at the
correct pressure, and makes it easy to check the coolant level.
How can I identify a faulty expansion tank?
Common symptoms include coolant leaks, cracks in the tank, a low coolant level, overheating, and
a dashboard warning.
Can a faulty expansion tank cause overheating?
Yes. If the expansion tank or radiator cap does not function properly, coolant may be lost or the
system pressure may drop, which can cause the engine to overheat.
When should an expansion tank be replaced?
Replacement is recommended if there are cracks, leaks, damaged connections, a faulty level sensor,
or if the plastic tank has deteriorated due to ageing.
How do I choose the right expansion tank?
Always check the OEM number, part number, or chassis number and pay attention to the capacity,
connections, mounting points, and any coolant level sensor fitted to the expansion tank.
For which truck brands are expansion tanks available?
BAS Parts & Tyres supplies expansion tanks for brands including DAF, IVECO, MAN,
Mercedes-Benz, Renault Trucks, Scania, and Volvo Trucks.