You add Freon on the low side with the motor running. The low side connection port for freon is much smaller in size compaired to the high side, so you can't put it in on the high side. If you are a novis at this, I suggest you buy the charge kit with a gage so you don't over fill the system,(if you over fill it it won't work properly)
R134a
where do I add freon to my air conditioning unit on a 1997 chevy truck?
to the low side
no
You always add freon using a set of gauges and you would use the low side (blue knob), if you are not using gauges then still use the low side service port but make sure that its a freon problem first...........
You can add Freon to your 1999 Chevy cooling system through the low pressure port. Connect your Freon bottle to the low pressure port and release the Freon into the system.
Freon is a very touchy thing to work with. The EPA bans its release into the atmosphere, so only experts and professionals know how to add and subtract Freon from the car safely. Take your car to a mechanic or a Chevy dealer for this.
Where is the intake valve / connector to add fron to my 2005 Kia Optima, with a 2.7l ^-cyclinder?
The schrader valve on the low pressure side of the system.
This is what I did for my Chevy prism 2000, it works fine: http://www.id-usa.com/how_to_recharging.asp
You add refrigerant through the low side service port.
The 2000 Chevrolet Silverado truck has two ports on top of the air conditioner compressor. You will add Freon through the low pressure port.