In a Mazda RX-8, the R134a low side charging port is typically located on the larger diameter line of the air conditioning system, near the firewall on the passenger side of the vehicle. It can be identified by its blue or black cap. Ensure the engine is off and the AC is set to the maximum cool setting before attempting to charge the system. Always refer to the vehicle's service manual for specific details.
All of your charging to your ac system is done through your low side port. The low side service port is located in the line that runs from the compressor through the evaporator (firewall) and up the condensor on the low pressure (suction) side of the system. R134a recharge hoses will only fit on the low side service port on all R134a vehicles and R-12 vehicles that have been converted to R134a.
it goes in the low-side service port located on the compressor, not the connector that is on the metal pipe leading into the compressor, that is the high-side that will cause the can of freon to pop, plus you need to get a retro fitting kit to convert the system from R124a to R134a, and before you add any of the R134a make sure to purge the system completely of all R124a
r12 but you can convert it by changing charging nipple on low pressure side which is on the compressor. you may not be able to get any r12 anymore. so buy a conversion nipple for 10 bucks at advance auto and buy a charging kit for r134a it holds about 24 ounces and 3 oz of oil
R-12 = 32 ozs. R-134A is similar. When charging you should be monitoring pressure anyway. I usually look for about 35 - 40 PSI on the LOW side.
On a R134a system the low side service port is the smaller one.
You can fill the AC on the low pressure side of the AC unit. Make sure and only use R12 unless your system has been converted to R134A.
refill port is on passenger side just below alternator.
The low pressure side.
There should be a sticker under the hood indicating whether it uses R12 or R134A. Unfortunatley a lot dont. The only way to tell is by the high and low side fittings. R12 fittings are bothe the same size. R134A has two different size fittings where one is larger than the other, ussually the high side fitting is larger than the low side.
You should just let the system take the refrigerant out of the can by itself. It is not good to force liquid r134a into the low pressure side of the ac. The suction of the compressor will draw the r134 out by itself and stabilize the system as it goes, it may just take longer than you want.
R134a goes into the low pressure port
low side never charge from high side