I have a '95 Nissan Maxima with 187,000 miles on it. I got into an accident and had to replace the condenser.

Question

..but am wondering if it is neccessary to vacuum the lines out before adding new refrigerant? How important is this to do, if at all? Thanks.

This is a R-134a system.

Answer 1

"Important!" But more important with new Parts! It also serves as a "Leak Down Test" Got any Residual Moisture out of the System. Helps To Pull the New Refrigerant into the System.

Answer 2

Up until 1995, R-12 was used in virtually all automotive A/C systems. But R-12 was phased out of production in the U.S. and many other industrialized nations because it is a chlorofluorocarbon (CFC), a manmade chemical that contains chlorine. R-12 and other CFCs were banned under the revisions to the Clean Air Act because scientists discovered that the chlorine from CFCs was destroying the Earths ozone layer. This region of the upper atmosphere shields us against harmful ultraviolet radiation from the sun. R-12 was replaced with R-134a, an ozone-friendly gas that does not contain chlorine.


RECYCLING AND VENTING
Federal law prohibits the venting of any type of refrigerant (R-12, R-134a or anything else) into the atmosphere, and the law requires R-12, R-134a and other "approved" refrigerants to be recovered and recycled when a vehicle is serviced. This creates a problem for service facilities if different refrigerants have been intermixed or a vehicle contains an unknown refrigerant.

To maintain the proper operating pressures inside an A/C system, the refrigerant must be pure and free from contamination. Contaminants include other refrigerants, air, flammable hydrocarbons and moisture. When two different refrigerants are intermixed, it changes the operating pressure and cooling properties of both. That is why R-134a should never be used to recharge an older R-12 A/C system, unless the vehicle is being totally retrofitted to R-134a. R-12 and R-134a are chemically different and require different types of compressor oils. If the mineral oil in an older R-12 A/C system is not replaced with POE or PAG oil when it is retrofitted and recharged with R-134a, a compressor failure may occur.

Vehicles should only be recharged with the same type of refrigerant that is already in the system unless an older R-12 system is being retrofitted. Though there are a number of EPA-approved refrigerant products that can be used in place of R-12 in older vehicles, the vehicle manufacturers and industry groups such as the Mobile Air Conditioning Society (MACS) say R-134a is the only refrigerant that should be used for retrofits.

Under no circumstances should anything other than R-12 be used to top off or recharge an older vehicle that still has R-12 in its A/C system. Mixing refrigerants causes cross-contamination and makes it impossible to recover and recycle the old refrigerant.

RELATED SALES OPPORTUNITIES
Any customer who needs refrigerant will likely need compressor oil too. If oil that has been lost is not replaced with the correct type and grade of oil, the compressors days may be numbered.

Replacement service fittings are another item that will be needed when converting an older vehicle from R-12 to R-134a. These are usually provided in a retrofit kit, which should also include a compatible compressor oil (POE or PAG). On some vehicles, o-rings or other seals may also have to be replaced. Some older compressors are also not compatible with R-134a (Kiehin and Nippondenso compressors with Viton seals in certain Japanese cars, and Ford FX-15 compressors).

A new accumulator or receiver/dryer should be recommended if a vehicle has lost all of its refrigerant, has been opened for service (replacing hoses, seals, etc.) or has suffered a compressor failure.

Since there have been some pretty substantial changes in the A/C category recently, it is important to keep up on the rules and regulations surrounding this product. It will keep your customer, business and environment safe.

Answer 3

If your system even has a drop of moisture it will corrode the inside of the A/C system and may even freeze at the expansion valve, The system has been open since the accident two weeks ago get the system on a 30 minute vacuum then add oil and refrigerant. If it was mine I would also replace the drier too. Say hellow to that flashing air bag light for me! Good Luck