Air Conditioner Vacuum and Recharge Guide and Video
When you have made a repair to the air conditioner system of your vehicle and the
system has been open moisture will get into the system, its unavoidable. After the
unit is back together it must be vacuumed down which can be done with a simple
vacuum pump and gauge set which are both available on Amazon for about
$119.00 this set can be then used for all future system repairs and while
helping family and friends.
If you would like to simply add rR134a refrigerant to your system, a recharge
kit can be used for about $27.00.
As an air conditioner ages the compressor, condenser, evaporator core and
hoses can leak or have mechanical failures which warrant replacement. I have
created this guide for you so you can do the repairs yourself and save money
while having the satisfaction of doing the job yourself.
These systems have a mixture of refrigerant and oil to keep
the air conditioning compressor lubricated during operation. Measuring the amount
of (pag) oil in the system is difficult because it's spread throughout the system,
in other words if there is a major leak and oil is dripping out, the system will
need a small amount of oil, unlike a very small leak which releases little to no
oil, you must be the judge of this.
Most manufactures recommend the system to be vacuumed down each time you
service the system to remove residual moisture which helps the compressor last
longer. An a/c system may look a little different from manufacturer to
manufacturer but follow the exact same principle.
It would be a good idea for you to know exactly how the system works so you
know what I'm talking about when working on the system.
Check out the video below to see how the job is done and then continue
reading below for tips and information you may have missed.
Each system has a specific amount of refrigerant needed to operate correctly
and is located in the owners manual or on the system itself, this guide will
successfully recharge the system even if this information is not available.
Tools and Supplies Needed
Air conditioner recharge gauge set and vacuum pump
Protective eyewear and gloves
Before beginning, park the vehicle on a level surface with the engine off,
apply the emergency brake with the transmission in park, wear protective eyewear
A fully charged system contains refrigerant under pressure (70 to 90 psi static - system not running), Allowing the refrigerant 134a to leak into the atmosphere is illegal though
not harmful compared to it's predecessor r12, which was slowly bled out of the system by
loosening a hose fitting at the gauge set.
This liquid/gas can be recovered if you have a recovery machine which most do
not, this machine is mostly found in
shops. Connect the gauge set to the low side charge port to check the start of
charge before beginning work. If you choose locate a garage to have the
refrigerant recovered before work begins. The recycling machine gathers refrigerant
along with a small amount of compressor oil which is then is separated into individual
Now that the failed component has been replaced you are now ready to vacuum
down the system, identify the service ports which the low side you should
already know. The high side port should be on the line between the condenser and
the expansion valve or orifice tube, remove the service port