floater Posted July 11, 2005 Share Posted July 11, 2005 I installed a new condenser and drier on my Outback. I then took it to repair facility to pull vacuum. They did so for 50 minutes and said it was okay. I then charged it with 2 oz can of r134 oil and 12 oz of r134. My manual says this model should hold 24 oz. It would not even take the full can of r134. Current pressure on low side said 25lbs. How long does it usually take for a can to be sucked in? The good news is the system works and Im cool in hot weather, just want to get it working at its full potential. 96 Outback Quote Link to comment Share on other sites More sharing options...
diluded000 Posted July 11, 2005 Share Posted July 11, 2005 I installed a new condenser and drier on my Outback. I then took it to repair facility to pull vacuum. They did so for 50 minutes and said it was okay. I then charged it with 2 oz can of r134 oil and 12 oz of r134. My manual says this model should hold 24 oz. It would not even take the full can of r134. Current pressure on low side said 25lbs. How long does it usually take for a can to be sucked in? The good news is the system works and Im cool in hot weather, just want to get it working at its full potential. 96 Outback I just (yesterday) replaced a hose, drier, and expansion valve on my truck and used one of those $15 air-compressor attached vacuum pumps from Harbor Freight to draw a vacuum, then charged the system with R134a. It took two tries to get the system completely charged back, but only took one can of coolant. One book I have suggests jumpering the thermostat that turns the compressor on and off, to keep it running continous while you recharge coolant - but I didn't try this. From what I gather, it takes some time for the system to get stable when doing a reharge, and the compressor has to be running for this to happen. You might try driving it around the block to get plenty of air to your condenser coil so the compressor runs longer, then hooking up the can and adding more charge. I put the coolant can in some water to help it keep from freezing up. This was my first try at this, but I am making cold air again. There might be some other way to get more coolant in there, but my high side/low side pressures are right, and I am cool so I'm not that worried about it. It might be possible to add more coolant when the temeprature is lower, I might try then. - James B Quote Link to comment Share on other sites More sharing options...
Legacy777 Posted July 11, 2005 Share Posted July 11, 2005 You guys need to let the refrigerent cans sit there for a little while. Set them in the engine bay where it's hot. It helps get most of the refrigerent out. I just redid my truck on saturday. Pulled a vacuum for about 30-45 min, Let the one can put as much as it could in without the engine running. When it stablized, I turned on the engine, and let it draw the refrigerent out of the can. Like I said, be patient. Quote Link to comment Share on other sites More sharing options...
floater Posted July 11, 2005 Author Share Posted July 11, 2005 thanks for the info from both of you. I didn't know you could had refriegerant without the compressor running? Anyway, I am going to drive it and use it for a while as diluded000 posted and then will recheck the pressure and maybe add a can. Quote Link to comment Share on other sites More sharing options...
diluded000 Posted July 12, 2005 Share Posted July 12, 2005 After driving for a day, I went home and put the rest of my original can of R134a, and a 2oz oil charge/2oz refrigerant in. To get the can empty I actually drove around the neighborhood with the can hooked up, and this seemed to work quite well. A also opened and closed the refrigerant can several times while I was charging, trying to let it get warmed back up between charges. I didn't hear the expansion valve hissing as much after I added some oil, and the A/C output while sitting idle seemed better. It felt colder on the way to work today, than it did yesterday. - James B Quote Link to comment Share on other sites More sharing options...
Legacy777 Posted July 12, 2005 Share Posted July 12, 2005 My expansion valve is hissing at me after my recharge. It probably needs a little more refrigerent. Quote Link to comment Share on other sites More sharing options...
diluded000 Posted July 12, 2005 Share Posted July 12, 2005 My expansion valve is hissing at me after my recharge. It probably needs a little more refrigerent. Mine quit doing that after the second charge. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted July 12, 2005 Share Posted July 12, 2005 hey - what is this expansion valve and what does it do/sound like? Quote Link to comment Share on other sites More sharing options...
Legacy777 Posted July 13, 2005 Share Posted July 13, 2005 hey - what is this expansion valve and what does it do/sound like? That's sort of loaded question, because in order to properly explain it I have to explain the entire ac system Anyway, here's a quick and dirty of the parts in your ac system, and how they work. The following is the order in which the refrigerent & oil go in. Compressor Condensor Receiver/drier Expansion Valve Evaporator The refrigerent is in gas form, and goes through the compressor, its pressure increases as well as its temperature. The refrigerent then goes through the condensor where it loses heat, and condenses into a liquid. The reciever is more or less a filter, and contains dessicant to help remove moisture. Next you have the expansion valve. The valve cuts the pressure & temperature of the refrigerent. The refrigerent also goes from liquid to gas through the valve. The cold refrigerent then goes through the evaporator where the air blows across it to get cold and go into the cabin. Then the process repeats. there's more theory behind it, but that's the jist of it. Here's a link with a pic http://home.howstuffworks.com/ac2.htm Quote Link to comment Share on other sites More sharing options...
idosubaru Posted July 13, 2005 Share Posted July 13, 2005 i've read through howstuffworks before but still wasn't sure why you can here the expansion valve. i seem to be hearing a quick burst at variable times on my OBS...10 minutes, 15, 7 minutes..i'll here a quick burst like someone is pressing a schrader valve in for a second. seems to only happen if the A/C is on, was wondering if this valve is doing that and if it's supposed to. Quote Link to comment Share on other sites More sharing options...
Legacy777 Posted July 13, 2005 Share Posted July 13, 2005 The expansion valve is basically an orifice. When you're low on refrigerent, it has to cut pressure quite a bit to maintain a cool temperature. The larger the pressure cut, the more noise you're going to get. Add some refrigerent and it should go away. I'm going to try and add some to my truck tonight. Quote Link to comment Share on other sites More sharing options...
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