Location of ac low pressure port location 2004 chevorlet avalanch

Depends on the year. Cars in the early 90's used R12. Anything later uses R134a. The size of the charge ports will define the R134a port. An adapter is needed to fit on the charging hose. R12 requires no such adapter. Ther charging label under the hood will tell you what refrigerant is needed too. Since you failed to give enough information on what make and model car you have, a general answer for the location of the low pressure port will be given. On the compressor, the larger diameter hose connection is the low side. Connect there, or look for the drier/accumulator (Large diameter silver container near the firewall). Connect there. You will need to access the AC information label under the hood to determine how much freon to add to the system.

There should be two ports on the ac lines, one is bigger than the other to help prevent you from connecting to the wrong side of the compressor. The ports are covered with plastic caps.

What your looking for is called a service port. On a 134a system there are two of them, located in the refrigerant lines. One port will be larger diameter than the other. The large one is the "high" side and the small one is the "low" side. refrigerent is added to the low side with the system running. You really should use a manifold gauge set to see what the pressures are before adding any refrigerant. If the system has too much, it is as bad as not enough.

Most likely low on refridgerant. ports are difficult to access .In front of passenger front wheel the accumulator is located. low pressure port is on top of it. Try and add a pound of 134a and see if it cools more efficiently. evaporators are common source of leak on these fine machines.

hmm ..if you are looking for the low side air conditioner port .. then locate the condenser (thats in front of and looks like the radiator) .. you will notice two tubes going to that ..one is large the other small .. the small tube is the high pressure side .. the large tube is the low pressure side ... follow the large tube back until you find a cap that covers the low pressure port .. thats where you would fill with new refregerant (r134a) .. if you buy r134a, you can also get a filler hose and gage.. that hose will only hook up to the low pressure port ..it wont fit the high pressure port ...

hook up an ac machine to the low side port only which is located behind the passenger side headlamp in the engine bay. evacuate the system then vacuum it for 15 min then recharge it with the specified amount of refridgerant. there should be a yellow sticker in the engine compartment telling you how much to add

Newer vehicle come with R134 vs R12. Since the two are not compatible, R134 has larger fittings. AC system has two ports, High and Low. Low is return to AC Compressor and high is output. High port is first following line from compressor to condenser (condenser is at front of vehicle like a second radiator). Keep following line till you find high port (paint cap red). Second port is low (paint cap blue).

look at the ac compressor and follow the large ac line/hose untill u come to the service port,,has it been retofitted for 134a? if not go to parts store and ask for a retro fit foe the low side,u will need to remove the sharader valve before installing the low side retro fit,,also purchase a charge hose

As long as your system uses r-134a and you are able to locate the low pressure side of the AC there should be no problem. Personally I have found that my local Big lots is the cheapest place to purchase the refrigerant. Something to think about before adding refrigerant is to make sure it needs it by either hooking up a gauge and checking the pressure. The easiest and least expensive way to do this would be to purchase the refrigerant with the gauge and hose for filling the AC attached.

Down low between the radiator and the engine. Look for the cap. Very hard to reach without burning your hand if the engine is hot. I had to rig a much longer hose to add 134a so the can would be upright while putting it in.