Pressurize A/C to find leaks?

You can easily put 50psi in the lines. Low pressure side is around 40 when in operation while high side will be 200 or more. Have you already replaced the o-rings that you just replaced? Seems most likely that one of those got nicked or rolled under upon assembly.

If you can't find the leak Second shot would be to put in 1 can of

134a and take it to an a/c shop with a sniffer. They can tell you pretty quickly what is leaking.

Steve B.

What do you propose to pressurize with?

Low side can jump to 2-3 hundred pounds pressure when compressor shuts down. There is no difference in pressure handling ability between the low and high pressure side.

Dried air from an air compressor.

Thanks folks! This is what I figured, but wanted to hear a few more opinions before I broke something.

I'm planning on checking all the joints this time, instead of only the ones that I needed to loosen to do my repairs.

Normal pressures on the high-side are close to 300 PSI. On the low side, operating pressures are around 30 PSI, and pressure with the system off can be around 100PSI.

To be safe, I wouldn't use any more than 50 psi to go leak hunting. That should be fairly sufficient. But it may still only spot a really big leak. To find really tiny leaks, especially in evaporator cores, you need a refrigerant "sniffer."

Air should be okay, assuming that he has lost most of the pressure already AND that he repairs and evacuates the system.

Of course, if a small leak is present in some hidden place, evaporator coil, etc., he may never spot it with soap bubbles.

The best way to find tiny leaks is with an electronic sniffer, but not everybody has that readily available.

I used to have one of those old torch type leak detectors and it was worthless for everything I ever tried it on. Thank goodness there are better tools out there today.

I've seen guys who were great with those. Definitely a skill to use, one that was beyond me too.

I do have a sniffer with a new sensor tip... Never had much luck using it, but I didn't have a whole lot of chance to actually test it out.

Thx!

Well, I do have a TIF5000 detector

but I've had little chance to get used to operating it. I'll definately try it out once I've done testing with pressure & soap solution.

Yeah those torch type leak detectors were better at turning refrigerent into nerve gas than finding leaks. The only person in this thread that I know of and would trust my AC sytem to is aarcuda. I'm suprised he's been silent about some of the post here. No offense but I don't think the OP is knowledgeable enough or equipped well enough to tackle the AC system. There are so many basics that aren't even being covered here or followed on.

What, you don't like the smell of phosgene in the morning? (for the few milliseconds you can smell it, anyway) :-p

That is quite probably true. But its also reasonably harmless to try to find a large leak with low-pressure air (50 PSI or less). It is interesting to note that most factory service manuals for R-134a systems advise against testing with air, because air/R-134a mixtures in just the right combination and at high enough pressure are apparently combustible.

I have always had a great respect for aarcuda, but AC work is not rocket science.

Some of the problems with amateur mechanics is a lack of understanding of AC systems, a lack of equipment to do proper diagnosis, and the tendency to do the job "on the cheap".

IMO, if you dont take the time, effort, and expense to do the job properly, you have just thrown away a lot of money.