How much will it cost to fix leaking air con on my car?

image showing volkswagen dashboard with air vents

Leaking air con is quite a common thing. A small amount of water always drips from car air con. Rather than this, we’re talking about the sort of leaking air con that prevents it working properly. The bad news is it can be expensive to fix an air con leak.

How much does car air conditioning leak repair cost in the UK?

This depends on what the problem is. Air con is tricky to sort out by the home mechanic. The refrigerant can be harmful to the environment so it’s best to get a trained technician on the job.

Unfortunately, if it is the condenser that needs replacing, it’ll be expensive. The part costs a lot and you’ll need to have the system fully charged with gas. Car air con leak repair cost will probably be at the thick end of £500, even if you have the job done by an independent garage.

By the time you’ve had the problem diagnosed and fixed, it could set you back as much as £1,000.

image showing a car's air con condenser
This is what an air con condenser looks like

Car air con leak repair

Leaking air conditioning is the most common reason it stops working properly. The system is closed and under pressure so even a pin prick hole can cause the coolant to leak away. The system also lives beneath the bonnet, in an environment that’s hot and can be liable to be damaged by errant stones.

Car air con uses a condenser to cool the refrigerant back down to ambient temperature. This happens after that refrigerant has been used to ‘condition’ and cool the air inside the car.

The condenser is usually positioned towards the front of the engine, ahead of the radiator but behind the front bumper. Look through your car’s grille and although you might think you’re looking at the radiator, what you’re probably seeing is the condenser’s fins.

Where is the most common place for car air con to leak?

While the condenser needs to be in this position to be most effective at cooling, it can be vulnerable to small stones being flicked up and fired at it by vehicles in front. If you’re unlucky, these stones will make a hole in the condenser causing a leak.

The air con system also has a series of seals. These are prone to drying out which results in leaks. To prevent this happening, it’s best to keep the air con on throughout the year, just adjusting the temperature and where the vents are pointing to suit.

How do you know if you’ve got leaking air con?

Your air con won’t lower the temperature so on a hot day the air coming through the vents will be just as warm as if you had the windows open.

If that’s the case, open the bonnet. With a torch, check the condenser’s fins at the front. If they’re leaking you’ll probably see some oily residue around them. The air con coolant has a small amount of oil it (this is what lubricates the seals in the system). If it’s leaking out, it’ll mix with the dust coming off the road and leave its oily mark.

A garage will be able to tell exactly where the leak is by adding dye to the system. Using a UV torch will highlight this dye, showing exactly where the coolant is leaking out.

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