J & J Auto Air - FAQs


Vital Facts About Your Car's Air Conditioning System

Car air conditioning, which was once a great luxury, is now a common feature on most motor vehicles. While the servicing of modern car air conditioning systems is best left to professionals, you can get the most enjoyment from your a/c system if you know a bit about how it works and what malfunctions you should be on the lookout for.

Why do I need to have my AC system serviced?

All vehicle air conditioning systems leak to a lesser or greater degree. The losses occur through refrigerant escaping through the pipe joins as a result of vibration and ageing of rubber hoses and 'O' ring seals, as well as through the seal on the front of the compressor shaft.

How often should the AC system be Inspected/Serviced?

An Annual Inspection is sufficient to check system condition and overall performance. A Service of the system should be carried out at least every two years even if it appears to be working well. It is estimated that you lose between 20-30% of the initial gas charge over a two year period and this figure is based on new vehicles.

Why does my fridge at home not need servicing every twelve months?

A domestic fridge has no rubber pipes and no seal on the front of the compressor shaft; all piping is copper therefore there is no leaking through pipe walls.

Is it true that the A/C system should be run often throughout the year?

Yes, this helps to keep the system well lubricated and leak tight.


Because the refrigerant actually carries the oil that lubricates the system, most importantly the compressor. It also keeps the seals and hoses moist, thus preventing them from drying out and cracking leading to leaks.

Why is looking after the compressor so critical?

This is the main component in the A/C system, replacements typically cost $1000 - $2000, plus labor costs to remove and replace. Also it usually follows that a seized compressor will result in other components getting damaged in the process.

What's involved in a service?

We measure the pressures in the system, check quality of refrigerant present. Check all functions. Then we recover the refrigerant and vacuum the system down to a very low pressure (Deep Vacuum process) to remove any moisture that might be present. We then Re-Charge (Re-Gas) with virgin refrigerant R134a The only Refrigerant Recommended by the vehicle manufacture and also add a measured amount of the correct type of lubricant for your system. We also add Ultra Violet dye to help find any leaks that may develop in the future.

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.

Why use Nitrogen for leak testing?

We use Oxygen Free Nitrogen (OFN) for leak testing. It would be illegal to re-gas a system to use the refrigerant as a means of leak detection. The pure form of Nitrogen is a naturally occurring gas in the air that we breathe and so is safe and legal to use. The Nitrogen is inserted into the system under high pressure thus simulating a system in operation and revealing any leaks in the system.

How do I know which gas is inside my vehicle's A/C system?

Generally all vehicles manufactured prior to 1994 used R12 and all vehicles manufactured after 1994 use R134a. Re gassing of the vehicles with R12 is prohibited as this refrigerant destroys the ozone layer. If your vehicle uses R12 it needs to be retrofitted to R134a