A/C slow leak

[alarmrick]

My air conditioning has a slow leak. I was going to just tighten all the fittings. Is it better to take them apart and use something like pipe tape or dope on the threads? There is no hurry as it is 32 degrees here but its a good winter project.

Thanks,

Rick

 

[Don C]

I would start by just checking to make sure all connections are tight. Check the service valves to make sure they are turned off. Most of the connections have a rubber seal, or o-ring, to seal them. A little mineral oil is all that is required when assembling them. Using any type of tape or compound would have the chance of getting into the system and plugging up the orifices or getting into the pump.

You can get A/C oil that has a dye in it to help locate leaks.

 

[alarmrick]

Thanks. That's what I needed to know.

 

[Bill73Ragtop]

My A/C system on my 73 has the same issue. Turned out to be a bad O-ring. Look at your connections - if there is black oily residue on the line at the connection that's the first place to check. I took mine into a local shop that still works with R-12. We pumped it down (at least what was left - not much) found the leak, pressure checked it, refilled it and ended up with 38 F coming out of the side vents. As the senior mechanic said, "there's no comparison if the system is operating correctly between R-12 and R-134"

That being said, sometimes it can be tough to find R-12 at reasonable prices, but the tougher part is finding someone with good operational R-12 equipment, experience and willingness to do the work. You can't mix the two so equipment has to be dedicated to the type of refrigerant. I found it interesting that I was the first person in 3 years to utilize this guy's equipment. Most have switched over to R-134. He was disappointed that he had purchased a supply of R-12 about 15 years ago along with the equipment figuring a lot of the classics would need maintenance now and then. He almost never uses it.