by Andy Kendall

Created on: July 29, 2008

To most amateur auto repair enthusiasts, any issues or problems with an air conditioning system usually require the assistance of a professional technician or a main brand dealer (for warranty purposes). There is, however a few DIY tasks that a person with some mechanical experience can tackle. For instance, recharging or sealing leaks in the system can be achieved with store purchased items, but there are a few golden rules to adhere by.

If your car is a 1994 or earlier model, you probably have an obsolete R-12 system and need to retrofit your system before recharging with the now industry standard R-134a. Check under the bonnet for a label or service plate indicating whether the system is R-12 or R-134a. Whilst carrying any works carried out on air conditioning systems, always wear safety goggles and gloves as coolant can cause frostbite.

If you are reasonably familiar with the layout of your engine bay, look for some large diameter metal tubing that runs between the evaporator unit (located inside the interior dashboard) and the main compressor (located in the engine bay). The low-pressure port would usually have a blue or black dust cap protecting the valve from debris entering it and causing leaks. The large diameter tubing will usually run from out of the main bulkhead and run around the outer edges of the engine bay before entering the compressor unit. Do not confuse this valve with the high-point valve located on the smaller diameter tubing; using this as a service point can cause cans of refrigerant to explode if attached. In some cases the low-point port valve may be located on the compressor body itself, but this depends entirely on the make and model of your vehicle.

If you are not overly familiar with the engine bay layout, I would suggest investing in a DIY workshop manual that is specific to your vehicle or consult your owner's handbook. These will be the best points of reference to finding exactly where the correct locations of service points are, as making an incorrect decision could turn out to be a very expensive mistake, not to mention it may also end up causing you personal injury.

If you are still stuck, I would suggest making enquires at your local motor factors/spare parts store and see if they offer an advice service as these people are often experienced technicians who will point out the correct locations to assist you in making a purchase.

If, after all this you are still confused, seek professional assistance. You can always watch them work and pick up some tips.

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