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Where to add freon?

9K views 16 replies 9 participants last post by  88TxVette 
#1 ·
After replacing the evap and compressor 5 years ago and checking for leaks (there were none) I've lost some freon and the system doesn't cool effectively (not very cold, and cycles) I just received some freon yesterday where do I add it? I know it goes on the low side, is it the connection of the cannister or somewhere else?

Thanks!
 
#12 ·
First you will need a license to buy it and about 700 bucks to get a 30 lb can and will need a charging hose. The best thing to do is take your car to a shop to charge the system and use dye to check for leaks or convert to 134a
 
#15 ·
If you want to be able to legally purchase R-12 refrigerant you'll have to get certified.
Go to http://macsw.org/certification.php
and get certified for $15. Online, open book test! Print out your certification online when you pass and they also mail you a wallet card and wall size certificate.

Shops do still recharge and auto parts stores carry R-12 refrigerant. Most auto parts stores carry the 12 or 14 oz. small cans and sometimes the 30# cylinders.
Your best bet if you do it yourself is find the R-12 on eBay. Most of the time you can get it for $20-$25 can max.
Full retail at Auto Zone and O'Riley's auto parts here in Houston is $36-$38 for a 12 oz. can.
Just don't use any Freeze 12 or mixture/add in type refrigerants. They are not SNAP approved by the EPA even though they are sold all over the place. The Freeze 12 is a mixture and is NOT good for your system.

Read up on the details from here:
http://www.macsw.org/pdf/CertmanualENG.pdf

And for the best auto AC forum:

http://www.autoacforum.com/categories.cfm?catid=2


Good luck with your project!
 
#17 ·
Be careful with that stuff! Hope they did all the proper retrofit requirements and not just a "drop in" charge! A dealership SHOULD know better than that!

Read on.......

FREEZE 12
ASU =ASU = acceptable subject to fittings, labeling, no drop-in, and compressor shutoff switch use conditions
Reviewed:10/16/96
Manuf.Technical Chemical 800-527-0885

Freeze 12 is a blend consisting of
20% HCFC142b
80% HCFC134a

From the
Certification Training Manual
Refrigerant Recycling & Service Procedures
For Automotive Air Conditioning Technicians
*approved by US EPA for technician training requirements under section 609 of the Clean Air Act.

Download the manual here:
http://www.macsw.org/pdf/CertmanualENG.pdf

Pages 22-24 of manual.
quote
There is no assurance that the A/C system will provide the same level of performance with the processed blend refrigerant as it did with new refrigerant containing the proper blend formulation.
Systems charged with blends may provide a high level of performance
when initially charged. However, each refrigerant in these blends has a different pressure/temperature relationship, and different leakage rates through flexible hose. These blends can separate while in use,
and a leak in the system can allow just one component of the blend to
escape from the system. This partial leakage can change the entire
refrigerant mixture and cause system operating problems.

Blend refrigerants contain more than one refrigerant, and have a bubble and dew pressure value
that affects A/C controls. This bubble and dew characteristic of blends results in a temperature difference across the evaporator and condenser known as “glide.” The auto industry doesn’t design
automotive A/C systems to use blend refrigerants. Installing blend refrigerants with the original A/C system refrigerant controls (expansion valves, pressure controls) could cause system performance problems. The automotive industry has always used single composition refrigerants such as R12 and R134a.



Page 26 of manual quote:

System Changes
Changes were required for HFC-134a systems to assure performance equal to systems using CFC-12.
Changes include new hose and seal materials which are compatible with the new refrigerant and lubricant. This includes new hose construction to reduce hose leakage, and a new desiccant material in the accumulator or receiver/dryer for reduction of moisture level in the system.
The most noticeable change, however, is the increased condenser capacity, or increased air flow, to reduce system pressures at low speed operation and city traffic conditions. In general, condenser performance has been increased by approximately 30%, which results in comparable performance for HFC-134a systems as experienced in CFC-12 systems.

http://www.epa.gov/ozone/title6/609/609.html
 
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