'99 coolant hiss from service port when removed

I just added some r134 last week to get some cool air from the AC. I don't think I got enough to fill the system cuz it improved but not totally. The clutch kicked off and on while I was adding and the low pressure came up a bit. I went to add more 134 and when I pulledn the cap off the fitting I got a hiss noise from the port. I think this is where my 134 is going but is this just a tire stem sort of valve that comes out the same as a tire? I have a stem tool to remove it with. Does Oreily's or Autozone have these valve stems?

I just added some r134 last week to get some cool air from the AC. I don't think I got enough to fill the system cuz it improved but not totally. The clutch kicked off and on while I was adding and the low pressure came up a bit. I went to add more 134 and when I pulledn the cap off the fitting I got a hiss noise from the port. I think this is where my 134 is going but is this just a tire stem sort of valve that comes out the same as a tire? I have a stem tool to remove it with. Does Oreily's or Autozone have these valve stems?


those valves sometimes get stuck..to replace you use the same tool as the valve stem on your vehicle..you must use the proper valve however.

adding refrigent at a minimum you must see what the low pressure is ..now if not and you overcharge the system you will destroy the compressor , this is a common mistake many not trained always do ..

Thanks jCat, got er done last night. I replaced the orifice tube while the system was open. It took a while to get enough in but it finally started blowing cold again. Probably not the best idea but I used the big can (22OZ) with the gage on the hose plus one more smaller can (18OZ) from Oreily's. They only sell r134 with sealer added that come with any sort of gage for reading the system. I know the "real Mechanics" out there are saying, "you cheap skate". Well, for as often as I do this, it ain't worth me buying a full gage set-up and areal bottle of r134. The sticker on top of the cannister mounted by the firewall said the system holds 2lbs 12oz and the guy at Oreily's said it probably won't hold all 22ounces since I wasn't sucking the system down with the "proper equipment" Anyway, the compressoer finally stopped cycling and low side pressure finished up at about 27 psi (IDLE ) on the cheesie gage on the hose. I checked pressures at 2k rpm as well while it was cycling and got form 23 to 65. 27 was just inside the "filled" band of the gage. I'm sure I could get more in to bring it to the middle or high side of that "filled range but without a pressure gage on the high pressure side, I think I'll see if I can live with it.

Thanks jCat, got er done last night. I replaced the orifice tube while the system was open. It took a while to get enough in but it finally started blowing cold again. Probably not the best idea but I used the big can (22OZ) with the gage on the hose plus one more smaller can (18OZ) from Oreily's. They only sell r134 with sealer added that come with any sort of gage for reading the system. I know the "real Mechanics" out there are saying, "you cheap skate". Well, for as often as I do this, it ain't worth me buying a full gage set-up and areal bottle of r134. The sticker on top of the cannister mounted by the firewall said the system holds 2lbs 12oz and the guy at Oreily's said it probably won't hold all 22ounces since I wasn't sucking the system down with the "proper equipment" Anyway, the compressoer finally stopped cycling and low side pressure finished up at about 27 psi (IDLE ) on the cheesie gage on the hose. I checked pressures at 2k rpm as well while it was cycling and got form 23 to 65. 27 was just inside the "filled" band of the gage. I'm sure I could get more in to bring it to the middle or high side of that "filled range but without a pressure gage on the high pressure side, I think I'll see if I can live with it.

they should have a cheap hose guage charge kit. about 15-25 dollars. I use this when I occationally add some to my fleet of vehicles.. when I work the big ac units you need the full guage set up..with most owners doing this on their vehicle as long as the system has no component issues this charging kit I use is all you need.

most importantly you must not install too much ...best be a little low...avoid using any sealers and refrigerent...with a vehicle several years old add 2-4 Oz of the proper refrigerent oil..over time the system losses oil as well as refrigerent...low oil causes seals to leak etc..

good luck..