I'm going to attempt to add some freon to my suburban and was reading up on it. I was trying to locate my high and low sides and noticed that they appear to be in the same pipe with a connector between to two. Also one side get's hot and the other becomes cold. Can someone explain this to me. It seems to me that the two ports would be in two different locations.

 

the system has a high pressure and low pressure side. the high pressure side is hot and the low pressure side is cold and has bigger diameter hoses.
One division between the high and low side is the orfice tube which is a restriction in the line that meters high pressure liquid refridgerent from the high side to the low pressure side which will then change state to a gas absorbing heat through latent heat of evaporation.

the service ports are located on either side of the orfice tube.


you will be contaminating your system adding coolant in a can. No shop will work on it as they won't recover the "cocktail of refridgerant" mixture you now have in your system.

 

Are you saying that refrigerant cannot be added to my system?

 

Ok, what i really want to know is looking at the picture below, are these two ports the low and the high side and the connector in the middle the orifice tube? I think the port that is nearer in the picture is from the compressor so that would be the high side, correct?

 

They're both on the same low side. That connector is the orfice.

 

the high side is the one before the closer to the comp. and will be hot to touch. the low side is closer to the firewall. and will be cold to touch. The orfice tube is locate between the 2 service ports.

Of course you can add refridgerent; anything other than 134a will contaminate the system. You also can't accurately add the correct amount of refrigerant will the can fill.

When a shop recovers an a/c system (removes the refridgerant), the machine will test the purity of the refridgerant first. If it is not pure because a different product was charged into the system they won't recover it so they don't contaminate their a/c machines tanks. A/c system sealer will also clog the valves of the machine.

You can add what you want but be aware if you need to get it worked on by a professional.

 

tech2. I see what you were referring to. I used the term "freon" which is incorrect. I have no intentions of adding anything other than R-134a to the system. I've been working on cars for many years and have an understanding of how A/C systems work but have always shied away from them. I have decided it's time to learn.

 

in that case...I'm assuming you have a leak and that's why your charging the system... recover the system and note the volume taken out. If its low, put a vacuum on the system, add dye and the amount of pag that came out during recovery. Charge the system to the proper amount through the low side. Run the system for and check for dye leaks with a uv light and glasses.

 

I found some brass plugs that replace the plastic caps on the service ports. The plastic caps did not seem to be able to contain the pressure. They always leaked. The brass plugs were a simple installation at a fraction of the cost of replacing the port valves. No need to bleed the system down or anything else. These may be available from fititparts@gmail.com.

 

The caps aren't supposed to hold any pressure. If the ports are leaking, then the valve needs to be replaced.