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Mobile A/C Service Facts and Fiction

Published May 19th 2008, 10:06pm by Jody DeVere in Featured Articles

Airconditioningrepair Spring is here and a new season of mobile air conditioning repair is ready to begin. The Mobile Air Conditioning Society (MACS) Worldwide sent us this release to remind both service professionals and consumers about the facts and fictions of A/C service. Some of these tips are highly technical, as they are aimed at service professionals, but it's important that even consumers read the bulletin, and it will help them understand why their technician may recommend certain procedures.

Manufacturers are now producing A/C systems that last longer and need less service. Changes include improved hoses, better sealing materials, and more robust connections. The goal, of course, is to provide consumers with reliable air conditioning on demand.

United States federal law requires anyone who opens the refrigerant pressure circuit "for compensation" (usually pay, but also barter, etc.) to be certified under Section 609 of the Clean Air Act. A shop can face serious fines for allowing un-certified employees to do this work. Technicians must have their certification available for inspection during the work.

The same law prohibits venting any refrigerant to the atmosphere. All refrigerant must be recovered. After recycling, it can be reused in a vehicle. If not recycled in the shop, then the refrigerant must be sent to a reclaiming facility.

Before beginning repairs, technicians must always use a refrigerant identifier to protect the shop staff and equipment. Not all refrigerants are the same, and mixing refrigerants is prohibited. Each refrigerant must be recovered with a specific machine into properly labeled tanks. Some gasses may also be flammable, presenting another hazard to technicians.

Refrigerant in the system does not need to be cleaned in the name of "maintenance." When the system is recovered, the refrigerant will be cleaned by normal use of refrigerant recovery and recycling equipment.

An operating system does not need additional oil or conditioners. In fact, additional oil may reduce cooling performance, and the use of incorrect lubricants may cause expensive damage. Technicians should always check the underhood label - most systems require a specific lubricant. A "universal" lubricant may not meet all of the manufacturer's specific requirements.

HFC-134a system lubricants are generally PAG-based, and the use of other lubricants is not approved by vehicle makers. However, POE lubricants are required for some electric compressors used in hybrid vehicles, and using PAG lubricants in those systems can result in mechanical problems and electrical hazards.

Autotrainingcentrecomimagestrades_f Read the label! SAE International has developed many industry standards for products and chemicals. Always look for a label statement that the product you are purchasing meets SAE standards.

Adding too much refrigerant to a vehicle's A/C system can reduce cooling performance. Many modern systems use smaller refrigerant charges than before, and the only way to assure maximum cooling performance is to maintain the correct charge. "Top-off" service is not the correct way to go.

Vehicle manufacturers install and recommend the correct products for their vehicles, and some systems now contain industry-approved trace dyes to aid in finding leaks. Manufacturers do not install other chemicals, system conditioners, or products intended to stop leaks. Vehicle manufacturers, parts suppliers and service equipment makers have all tightened their warranty policies regarding use of non-approved substances in their products. Chemical additives and other products may cost your shop and your customer a lot of money.

As the A/C system ages, some loss of refrigerant is unavoidable, and cabin cooling will be reduced. A quality service shop will have the knowledge and equipment to find the leak quickly and perform the correct repair. Adding a sealer to a leaking refrigerant system may not be the answer. Some aftermarket chemicals have caused damage to components and service equipment. Adding any other chemicals into a customer's A/C system may become a costly mistake.

Refrigerant leaks should be identified and the leaking parts replaced with quality components. Adding refrigerant to a leaking system does not make economic sense for the customer and also contributes to atmospheric pollution. While some consumers still want the low-cost option of constantly adding refrigerant, it's up to shop professionals to convince them that the bandage approach doesn't cure the real problem and may cost more if the compressor ultimately fails. A professional service facility will strive to provide the customer with cost-effective repairs that return the system to reliability and preserve the environment.

Today's newer, smaller, and tighter systems are just the beginning, and many more changes are coming in the next few years. Technicians need to be ready so they can offer the best possible service to their customers. And customers need to be educated so they can better understand their technicians when they explain about these complicated systems. Learn more at

Brandy_schaffels_s By Brandy Schaffels Editor

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