I need to add freon and am not sure i have the low side port. It has a black cap on it and is like a big valve stem but metal. I have charged systems before, but the guage i got and hose is to small to fit over this fitting. I have never had to have any kind of adapters to charge any other ones with r134a. Is this the right port or do I need some adapter. Let me know where the port is at or what I need. 97 eb with rear air

 

That's the high pressure port. The high and low ports are two different sizes (high is larger than the low) to keep people from mixing them up and blowing up cans of refrigerant in their hand.

 

found it and added 18oz. it took it fast and it seemed to get colder, but not cold enough. clutch is staying on and not kicking off. the guage was showing blue which is supposed to be full, but seems like it needs either all new or more. what do you all think.

 

First off, if it took that much then you have a leak that needs to be fixed. Second, was it on the low side of the blue part of the gauge or the high side of it?

 

it was on the middle of the blue. it did get colder than it was. but not cold enough

 

You cannot tell how much refrigerant is in the system by the pressure shown on the gauge. The best way is to evacuate the entire system, put a vacuum on it and then recharge the system with the correct amount of refrigerant. Also add some dye to the system before you charge it again. After this is done you can check for leaks and for a plugged condenser or whatnot.

 

My daughter has a 2001 and I can't seem to find the low side port. Any tips?

 

It's on the accumulator right next to the firewall. It's hiding under the wiring harness and is not very easy to get to on some models.
JL

 

Mrcmk is correct. Just adding some refridgerant to the system is like using a wad of chewing gum to fix a leak in your oil pan...................It ain't gonna work very well. Sevice the system to get the maximum cooling efficiency from it. Dan.