You can find the location of the service valve where you add refrigerant on a 04 Jetta on this web site alone with very helpfull information www.idqusa.com just click on locate low side port.
I have a 1996 land rover 4.0 and need to add freon. I have the gauge, but don't know where to connect it to
With the Freon and gauge connected to the low side ac port, start the engine. Turn ac on high, and add Freon till the gauge shows full.
Never add freon to your own car. This is very dangerous and can kill you. A/C systems are very high pressure and If you buy a freon kit to add freon to your car. It will be propane which is highly flammable. Take it to a dealer to get it done. Also if you ever add it and it is leaking out then it can explode if it gets near a spark.
Use a freon gauge and freon refill can. Connect the gauge to the low pressure ac port of the 2003 Stratus. With the engine running and ac on high, fill the system until the gauge shows full.
Freon is added into the low side ac port. Using the proper type Freon, and a gauge that works with that type Freon, connect the hose to the port. With the engine running allow the Freon to flow until the gauge reads in the ok range.
R134a
You'll need a pressure gauge and know how to use it. The gauge will tell you when you have the right amount in.
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Which do i hook to to charge the freon in a 2004 ford expedition
To add freon to a refrigerator, you will need to locate the access valve on the compressor unit, connect a charging hose to the valve, and slowly add the appropriate amount of freon using a refrigerant gauge. It is important to follow the manufacturer's guidelines and safety precautions when adding freon to a refrigerator.
Connect a freon gauge and tank to the low side ac port of the 97 DeVille. With the engine running and the ac on high, open the freon valve. Shut the valve when the ac gauge reads full.