Below you will find some of our more frequently asked questions. If there's anything you think we should add here please get in touch. We will keep adding to the list so please re-visit for updates.
Are you qualified?
Yes. Certification is required by law for all personnel servicing vehicle air conditioning systems, handling or storing refrigerants.
How often should my vehicle's air conditioning systems be serviced?
Unlike the domestic fridge, automotive air conditioning systems operate in a harsh environment and are subject to moisture, vibration, extremes of temperature and mechanical shock. Service intervals can vary depending on the conditions of use and the annual mileage of the vehicle. For average use and 12,000 miles a year intervals of every 12 months to 18 months should be sufficient to ensure the air conditioning and all components operate at maximum efficiency. Vehicles that are used off-road or have annual mileages of over 24,000 miles should be serviced more often.
What's involved in a service?
We measure the pressures in the system, check the quality of refrigerant present to make sure that it is not contaminated and check all functions. Then we recover the contents of the system separating the refrigerant and oil. The process involves subjecting the entire system to a complete deep vacuum which causes any moisture in the system to boil off. We then re-charge the system with the required weight of refrigerant and replenish the lubricant. At this stage we can also add a UV dye that will show up any future leaks under ultra violet light.
How long does it take to service the air conditioning system on an average car?
A straightforward service where there are no faults to rectify will take approximately 30 minutes. Where leaks are found or essential repairs are required a further appointment for repair may be required.
I have my car regularly serviced, surely the air conditioning system is part of the service and can be performed by the garage?
Most garages and many main dealers do not service car air conditioning systems in house. They employ specialist air conditioning engineers like ourselves. It is generally not cost effective for them to train and have certified staff who may only occasionally work on a system. At Autokool we have carried out work for many main dealers in the past so can offer you the same service if not better at a fraction of the cost.
Why does my car air conditioning system run low on refrigerant?
A/C systems will tend to lose refrigerant over time as refrigerant permeates through the physical joints between components. In normal working conditions all automotive air conditioning systems will lose about 10% to 15% of refrigerant each year which is considered natural leakage. Letting the system run low on refrigerant which in turn provides poor oil circulation can lead to wear and even serious component failure.
How much refrigerant does an average car's air conditioning system take?
It varies with make and model. The amount of refrigerant required is specified by the manufacturer and is measured by weight and not pressure which is a common misconception. A small family car may take 500g; a large executive saloon's air conditioning system with climate control may take over 1kg.
How often should I run the air conditioning in my car?
Ideally, all the time. It is false economy to turn the system off in the winter. This can lead to deterioration of the seals and gaskets in your system and, even more rapid refrigerant loss. On the coldest of days turn the system on to ensure that the windows are demisted and the interior of the car is comfortable. Contrary to popular belief this does not greatly reduce your mpg or performance. With modern engines and increased fuel efficiency the cost of using your vehicle air conditioning system has been considerably reduced with modern advancements in engineering.
When I switch my air conditioning system on I get an unpleasant damp smell which eventually clears, what causes it and how do I get rid of it?
The smell is the result of bacteria/algae breeding in the condensate that collects in the system. The by products produced by the bacteria are what cause the unpleasant odours and often cause allergic reactions, coughs, sneezes and sore throats. As part of any service we recommend that the pollen filter is inspected and changed if necessary and the system treated with an anti bacterial spray to eliminate any unpleasant odours.
How do I check that the air conditioning system is working when I buy a second hand car?
As with the vehicle itself, first check the service records and any available receipts. If the vehicle is more than two years old it should have had the air-conditioning system serviced. Start the engine turn the heater setting to the coldest setting and maximum fan blower speed. The air from the heater vents should be almost freezing cold within a minute or so. Also, you should be able to hear slight rise and fall in engine tone as the compressor clutch clicks in and out. Most air conditioning systems have fans that are sited in front of the radiator and can been viewed through the vehicles front grill. These should also be turning. These are separate to the engine cooling fan that typically sits behind the radiator and can be seen by lifting the bonnet.
If the gas leaks into the passenger compartment of my car can it be dangerous?
No, the modern refrigerant, is not poisonous, harmful to health or an explosive gas. It is also relatively environmentally friendly unlike the old R12 refrigerant gas which was phased out from 1993.
Why put Ultra Violet (UV) dye in the system?
The UV dye shows up under a bright UV light source. So any leaks present in the system can be easily identified either during fault finding or if future leaks were to develop. The addition of UV dye to a system is strongly recommended to aid future leak detection.
Why can't I service the system myself?
This is difficult not only because specialist equipment is needed but most importantly the refrigerant present in the system must be recovered. It is ILLEGAL to vent the refrigerant into the environment. The system is also under high pressure and needs pulling down to a total vacuum to remove any moisture. The refrigerants themselves have a very low boiling point and will cause freeze burns if they come into contact with skin or eye tissue.
Why should my gas in my air conditioning system be analysed?
Our gas analyser can reveal whether or not your gas is the correct type for your vehicle air conditioning system and whether or not it is contaminated which would strongly suggest a leak in the system. The wrong type of refrigerant could also bring about the premature failure of the compressor as it may not be able to carry the essential lubrication around the system. It is also important to check for moisture and air in the system.
I drive an older vehicle that is equipped with air-conditioning and it uses the R-12 type of refrigerant. Can I still get it repaired if I need to this summer?
Due to environmental legislation it is now impossible to offer R12 refrigerant. For older vehicles (pre 1992) fitted with R12 systems we offer a number of service options.
- R12 refrigerant replacement known as RS24. RS24 uses compatible mineral oils and therefore requires no changes to compressor, dryer or pipe work. RS 24 is more expensive than R134a but assuming your AC system is sound it can be a more cost effective solution to retrofitting with R134a.
- Retrofitting Air Conditioning systems with R134a refrigerant. Your system will need any R12 removing or if empty pressure testing to ensure the system is not leaking. Re-charge with RS24 and add compressor oil. This also involves changing the system oil, gas and service port connectors to the modern equivalents.
I own a classic car. How can I get replacement parts that are no longer available off the shelf?
We have a list of specialist companies that we work with that will adapt 'off-the-self' compressors, condensers and heat exchangers or even factor bespoke units. We carry the necessary tools and equipment that enables us to factor replacement pipe work, service ports and associated components that connect the clever bits together.
I have recently had my air conditioning system topped up but it has stopped working again, what could it be?
The simple answer is you probably have a small leak. Over time refrigerant will work its way out of even a healthy system never mind one that has recently required filling or has been re-gassed for the first time after a long period of being out of service. The only way to be sure is to use specialist gas detectors that can detect incredibly small amounts of refrigerant that would never be picked up with traditional pressure testing. Also the detector can be safely used whilst the system is functioning testing for traces of refrigerant in the heater ducts and hard to get at areas of the engine bay.
How can I tell if my auto A/C system is low on refrigerant?
The truth is, there is no easy way to tell if your A/C system is low on refrigerant. The pressure gauge readings provide a pressure, not the amount of refrigerant in the system. Therefore, connecting a set of pressure gauges and taking a pressure gauge reading will not tell you that the system is low on refrigerant. The only way to make sure you have the correct amount of refrigerant in your system is to evacuate the system with a vacuum pump and recharge with the correct weight of refrigerant specified by the manufacturer.The presence of odours or poor cooling output on warmer days is also a strong indication of an under charged system.
The A/C Clutch will not engage. What could the problem be?
There are several different reasons why the A/C compressor clutch does not engage when you turn the A/C system on. The most common problems is that you're system is low on refrigerant which is preventing the pressure switch from engaging the compressor. That's because it's acting as a safety for the compressor. It is not recommended that this safety switch be bypassed as it could cause serious damage your system and vehicle. What is also becoming more common with the very wet weather we are having is the clutch mechanism becoming seized with corrosion and/or debris picked up when fording flooded roads. The nature of air conditioning is the compressor; to work well and receive optimum lubrication is usually mounted at the lowest point of the system, which means low down in the engine bay. Driving through floods can seriously damage your compressor.