Question: How do I add Freon to my Volvo AC System.
Answer: AIR CONDITIONING RECHARGE PROCEDURE
1. Connect the recharge service hose and valve to a can of the correct refrigerant.
R12 for older cars that have not been converted.
R134A for newer cars or ones that HAVE been converted.
2. Turn the valve on the service hose to puncture the top of the can.
3. SLOWLY turn the valve back out to release a small amount of refrigerant into the hose.
This will blow air out of the hose (which you do not want in your A/C system).
4. Close the valve so no more refrigerant escapes, then quickly connect the other end of the service hose to the LOW pressure service fitting on the A/C system.
CAUTION: DO NOT connect a can of refrigerant to the HIGH side service fitting.
The operating pressure inside the A/C system when it is running may exceed the burst strength of the can, causing the can to explode!
This should be impossible to do because the service hose for recharging the A/C system will only fit the smaller LOW pressure service fitting.
Even so, you should be aware of the danger.
5. Hold the can UPRIGHT so no refrigerant liquid enters the service hose.
You only want VAPOR to be pulled into the A/C system (the compressor may be damaged if it sucks in a big dose of liquid!).
6. OPTIONAL BUT HIGHLY RECOMMENDED: You should use a gauge to monitor the recharging process.
Though not absolutely necessary, a gauge will help you recharge your A/C system more accurately,
and reduce the chance of undercharging or overcharging (either of which will reduce cooling performance).
A high pressure A/C gauge can be connected to the HIGH pressure service fitting, or a low pressure A/C gauge to the LOW pressure service fitting,
or gauges can be attached to both fittings (that is what professional technicians do).
NOTE: Some DIY recharging kits include a low pressure gauge on the service hose or on a trigger-grip style can dispenser