Cost to replace radiator bottom hose

What is a radiator bottom hose?

Your car’s engine has multiple moving parts which create friction and heat. Oil lubricates and removes heat from internal components and coolant is used to remove heat from the engine by flowing through channels inside the engine block.

The cooling system uses a thermostat which identifies when the engine reaches operating temperature and will allow coolant to flow through when required.

The coolant is pressurised and travels through the cooling system by means of a water pump.

The coolant absorbs heat as it travels through the engine. It makes its way into the top radiator hose and down into the thin fins of the radiator, where it cools down.

This is where the coolant will then pass through the bottom radiator hose back into the water pump and back through the engine, where the cycle continues.

The bottom radiator hose is designed to handle heat and pressure and is specifically shaped to fit your particular vehicle.

As the hose is not flexible you do have to use the correct hose for each type of vehicle.

Symptoms the bottom radiator hose needs to be replaced

• Faulty radiator cap which creates pressure issues in the cooling system
• Leaking coolant may be noticeable under the car or around the hose, or you may notice that the coolant level is down
• When the engine is warm, if the hose feels either hard or soft and spongy when you squeeze it, that’s not good. Ideally, the hose should be firm to the touch
• You may notice that your engine is running hotter than usual and even overheating
• You can physically see the hose is damaged or has collapsed in on itself

How is the bottom radiator hose replaced

• Engine needs to be cool before commencing
• Mechanic will check and inspect suspect hose
• Radiator cap is removed
• The coolant will be drained from the radiator into a container
• Clamps on the faulty radiator hose will be unclasped and the old hose removed
• Attachment fittings will be cleaned
• Clamps will be placed onto new hose. If old clamps are still good they can be reused, but it is recommended new clamps are used
• New hose will be positioned and clamped into place
• Coolant drain plug at base of radiator will be tightened
• Coolant mixture added. Only reuse the old coolant if it is reasonably new and uncontaminated
• Start the car and wait till it gets to operating temperature and the thermostat opens
• Check for leaks and top up coolant level in the radiator and coolant reservoir, after the thermostat has opened
• Replace radiator cap
• Drive vehicle and continue to check for leaks and be aware of the warning signs that the coolant level has dropped

Tips to remember

Replace the hose clamps whenever possible. Clamps can fail over time and this is more likely after they have been undone and retightened.

Top up coolant after the thermostat has opened. Levels will usually drop once it has run through the engine.

How important is replacing the bottom radiator hose

If you have a faulty, damaged or missing bottom radiator hose, you shouldn’t drive. This is a part that should be fixed straight away.

If you were to continue to drive, you run the risk of overheating the engine. This could cause irreparable damage and result in the engine needing to be replaced, costing you thousands of dollars as well as plenty of inconvenience.

An awesome technician is available at AutoGuru to help you get back on the road.