Finding an A/C Leak

So the A/C in my Miata died about a week ago. Compressor still works, idles up, etc., but no cold air. So I think the refrigerant has leaked out. I'm going to go ahead and replace the o-rings, etc. this winter, etc. However, is there any way I can find the leak ahead of time before recharging? I'm wondering if I took a rock to the condenser, or if it is just the seals have gone bad.

Thanks!

sure you just need a halogen detector and some N2. Preasureize the system with N2 and check with the sniffer theres enough 134 left to find it

If you lost all of your refrigerant your compressor wouldn't engage. You may have lost enough to degrade performance. Most of our repairmen use soapy water to check for leaks. I know that may be hard to believe, but they say it's the most reliable way to find a leak. Leak detectors can give false readings, especially in an engine compartment with the engine running. Dye and a black light can work, but only if you previously put dye in the system. I'd put a set of gauges on it to see if the pressures are in line or not.

Get a can of R134 with Dye in it from AutoZone, Wal-mart, etc. That way you charge your A/C if the system is just low and keep it working for the rest of the summer. When it leaks out you can then use a black light and glasses to find the leak. Autozone also sells a mini black light with yellow glasses for about $15. If you want something nicer and brighter check ebay for some hand held black light. There are a bunch of mini ones out there that people use to find scorpions.

I did the 134 with dye. I haven't fixed it yet, but I do believe I found the leak. I got one of the little LED lights people use to find scorpions at ACE hardware.

I was thinking Snoop, same stuff my dad uses to find leaks at his work. Like soapy water but doesn't leave a residue.

http://www.swagelok.com/leak_detectors_lubricants_sealants/liquid_leak_detectors.htm

UPDATE: Did some diagnostic work today. Found out the A/C compressor clutch is not working. I am getting 12V to the compressor, the engine idles up, but the clutch does not engage.

Any ideas on how to fix other than replacing the compressor? At this point, I'm just going to leave it until winter to fix. Is there a way to rebuild the clutch mechanism without removing the whole compressor and bleeding the system? Thanks!

The clutch may need to be shimmed. I know on Ford clutches as they wear you can shim them in to get them to engage. Possibly Mazda used the same compressor.

First, use a meter to check that the clutch coil is not open or shorted. Ought to be around 1-2 ohms resistance, varies with model. Zero, or infinity ohms is bad. Next, make sure that the ground side of the clutch coil is actually grounded. In most cases, the clutch can be replaced w/o removing the compressor. Might need a bearing puller, and might need to to unbolt the compressor to position the unit for clearance (without opening up the refrierant lines!).

Good luck.