Where is my A/C Low Pressure Port Located?
05-11-2010, 06:56 PM
#16
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05-11-2010, 08:18 PM
#17
Three Wheelin'
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I'm confused. Didn't you say earlier that your car had the R134a retrofit ports on it already?
Your best bet might be to find a decent A/C service center in the area. They can vacuum test the system. If it will hold vacuum, then they can charge it. If it runs once charged, great. If it leaks once charged, they should at least be able to tell you where it's leaking (before they pull all the refrigerant back out). If it doesn't leak or run, they'll probably be able to give you some idea of what else is wrong.
I'd expect $50 - $200 for something like that. Depending on whether all it needs is a full charge of R12 (closer to $200) or there's some major leak or other problem (closer to $50 to diagnose - not to fix).
Your best bet might be to find a decent A/C service center in the area. They can vacuum test the system. If it will hold vacuum, then they can charge it. If it runs once charged, great. If it leaks once charged, they should at least be able to tell you where it's leaking (before they pull all the refrigerant back out). If it doesn't leak or run, they'll probably be able to give you some idea of what else is wrong.
I'd expect $50 - $200 for something like that. Depending on whether all it needs is a full charge of R12 (closer to $200) or there's some major leak or other problem (closer to $50 to diagnose - not to fix).
05-11-2010, 08:28 PM
#18
Chronic Tool Dropper
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As Dan deftly points out, there's a lot more to getting a system to work than connecting a can and adding gas to it. If the system has leaked, there's a good to great chance that oil has leaked out with the gas. If the system is truly empty, you'll need to evacuate it after putting a new drier in, at minimum. In my opinion, it's better to fix leaks before you evacuate and recharge too. For that you'll probably want to identify the leaks. You'll want to see if the 'conversion' was done close to correctly, with the correct o-rings/hoses/oil at minimum.
The OP was about the location of the low-side port. That's been answered I think.
The OP was about the location of the low-side port. That's been answered I think.
05-11-2010, 09:22 PM
#19
Three Wheelin'
Thread Starter
I thought it was converted but apparently not. Guess I won't be doing much driving in the coming months.
05-11-2010, 10:45 PM
#20
Brian, bring it back up, if the compressor is still good, you've only got an expansion valve, drier, and about 15 seals. Talking a few hours and under $100.00 in parts plus R-12.
05-11-2010, 11:54 PM
#22
Three Wheelin'
Thread Starter
So your saying that if I take a road trip to Denton and slap a $100 in your hand I'll be able to cruise home with a/c?
James, do you smell a road trip in our future?
James, do you smell a road trip in our future?
05-12-2010, 12:53 PM
#24
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05-12-2010, 01:18 PM
#25
Three Wheelin'
Thread Starter
I found a can of R-12 and the hose attachment here at the shop at work, so we'll see what happens.
05-13-2010, 03:30 PM
#26
Three Wheelin'
Thread Starter
There's a really good case for charging the system with the engine COLD and NOT RUNNING. Biggest is that it helps you avoid the burned hands and arms around that upper hose. Next is that it's much faster to push liquid into a non-running system. Hook up the hoses, and charge LIQUID by holding the can valve-down, and adding a little heat to the can. Depending on system ambient temp, this could be as easy as holding it in your hands to warm it up. If system ambient is over 90º or so, you may want to use some warm (no greater than 120º) water in a pan or bucket. That will push liquid from the can through the hose, and that liquid will flash to vapor after it's in the car system. Wait a bit before you start the car and turn on the AC, so there's no chance that there's a slug of liquid going into the compressor suction.
Thanks again.
05-13-2010, 07:50 PM
#27
Three Wheelin'
Thread Starter
Didn't work. I started it up and drove a few blocks w/the A/C on and not too cool. It did stink up the garage a little.
05-13-2010, 08:19 PM
#28
Chronic Tool Dropper
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Brian--
There's a whole lot more to AC systems than putting a can of freon in it. Reiterating, if the system was down to no pressure due to leaks, the leaks need to be fixed or adding freon will be a short-lived solution at best. If the system has no pressure, air (and moisture) get in the system with pressure/temperature changes, and that means a new receiver/drier as part of that effort. You'll want to add the correct amount of oil to the system to replace what's leaked out, and that means the compressor is out, gets drained and refilled. Then all the air is sucked out of the system with a vacuum pump. Less air in the system is better, since air does nothing for cooling. It does 'fool' the expansion valves enough that you can easily see vent temps 15-20º higher even with just a little air. Plus air hogs condenser capacity. After all of that, you can add freon. My S4 needs the equivalent of between three and four of those little cans, plus what's lost when the external hoses are purged of air. One can does nothing, unfortunately. For the average Joe, the cost of even the basic AC tools makes pro service look attractive. There are plenty of opportunities for DIY support of a system refurb, like replacing hoses and seals, the drier, and doing the oil in the compressor. Ultimately the evacuation, leak checks, recharge and performance analysis may best be done by a pro though.
There's a whole lot more to AC systems than putting a can of freon in it. Reiterating, if the system was down to no pressure due to leaks, the leaks need to be fixed or adding freon will be a short-lived solution at best. If the system has no pressure, air (and moisture) get in the system with pressure/temperature changes, and that means a new receiver/drier as part of that effort. You'll want to add the correct amount of oil to the system to replace what's leaked out, and that means the compressor is out, gets drained and refilled. Then all the air is sucked out of the system with a vacuum pump. Less air in the system is better, since air does nothing for cooling. It does 'fool' the expansion valves enough that you can easily see vent temps 15-20º higher even with just a little air. Plus air hogs condenser capacity. After all of that, you can add freon. My S4 needs the equivalent of between three and four of those little cans, plus what's lost when the external hoses are purged of air. One can does nothing, unfortunately. For the average Joe, the cost of even the basic AC tools makes pro service look attractive. There are plenty of opportunities for DIY support of a system refurb, like replacing hoses and seals, the drier, and doing the oil in the compressor. Ultimately the evacuation, leak checks, recharge and performance analysis may best be done by a pro though.
05-13-2010, 11:55 PM
#29
Three Wheelin'
Thread Starter
Thanks Dr. Bob.
