In order to remove all the refrigerant from later-model vehicles during the recovery process, a J2788-compliant A/C machine is required. This is due to later-model vehicles using less refrigerant, which older A/C machines cannot fully recover, leading to potential problems.
For example, if an older A/C machine leaves behind 30 percent of the refrigerant after a Recovery, Vacuum, Hold and Recharge, and one then performs a full charge, the A/C system becomes overcharged, which will cause performance issues and cause premature component failure.
Machines such as the Bosch ACS-615 are designed to exceed the J2788 standard, consistently recovering the maxium old refrigerant, preparing the A/C system for recharging.
If a shop already has a J2788-compliant machine, make sure it is ready for hot weather A/C service by changing the vacuum pump oil, keeping a spare filter on hand, and keeping the tires properly inflated. Underinflated tires can cause the refrigerant scale to be out-of-calibration not an issue with machines which use foam filled tires, such as the Bosch ACS-615.
Other tips include:
Use a refrigerant identifier and check virgin cans of refrigerant. A mixture of 134a and R22 can damage J2788 machines.
Check for sealant leaks. Sealants can kill the A/C machine. (a very inexpensive sealant tester is available from Neutronics).
Use a filtration system to handle vehicles with traces of seal. Keep in mind that you need to open the cleanout drain after every service to measure the amount of oil removed. (AirSept offers an inline filtration system called RecycleGuard. These filters are quickly installed inline and remove sealant, dye and lubrication).
There is also a new standard for leak detectors: J2791, and current equipment is certified to catch leaks as small as a 1/4 ounce. The companies making these detectors are also required to tell you about chemicals that provide a false positive.
In addition, some A/C repair issues cannot be resolved without reprogramming the vehicle’s computer system. On that note, it’s always a good idea to take some refresher courses to get up-to-date with the latest diagnostic techniques for air conditioning weather.
Bosch is a proud supporter of the Automotive Aftermarket Suppliers Association’s Know Your Parts education and awareness campaign. This initiative promotes the importance of quality brand name aftermarket parts backed by full service suppliers, and its impact on delivering reliable products to today’s motorists. For more information visit: http://kyp.aftermarketsuppliers.org.
Source: Bosch Diagnostics Business Unit