A/C Leak Testing Using Compressed Air, Soap and Water (any car)

I NEVER MIXED COMPRESSED AIR WITH THE REFRIGERANT! IT WAS EMPTY FROM A LARGE CONDENSER LEAK!
Some of you want to argue, that what I showed was unsafe. Please tell me how an empty system, filled with compressed air, is a safety concern. I'm not asking about the supposed contamination. I am asking about the safety side of this procedure. I certainly do not endorse unsafe practices.

Here is something I found on a Google search from some engineer forum...

HFC-134a is not flammable in air at temperatures up to
100 deg. C (212 deg. F) at atmospheric pressure. However, mixtures of HFC-134a with high concentrations of air at elevated pressure and/or temperature can become combustible in the presence of an ignition source. HFC-134a can also become combustible in an oxygen enriched environment
(oxygen concentrations greater than that in air). Whether a mixture containing HFC-134a and air, or HFC-134a in an oxygen enriched atmosphere become combustible depends on
the inter-relationship of 1) the temperature 2) the
pressure, and 3) the proportion of oxygen in the mixture. In general, HFC-134a should not be allowed to exist with air above atmospheric pressure or at high temperatures; or in an oxygen enriched environment. For example HFC-134a should NOT be mixed with air under pressure for leak testing or other purposes.

Using that method for more than 10 years already. Im using an old AC compressor to pressurized parts.

how many psi did you charge the low side?
Goodbye and thanks

So, a compressor shaft seal cannot be found to leak? How about bubbles kids use? I bet it would blow large bubbles out of the compressor seal.

It was emty with refrigerant how on earth this will become combust ible were there is no mixture it just common sense.😂no mixture no combustible thats it.when it comes for compressor to be damage its not your problem its tech whose doing the repair.thats it😂

Lets get this straight. You are recommending that people run their ac with no oil and also that they inject a bunch of moisture (from the compressor) into the system??

The right way to pressure test a system is with dry nitrogen. Air contains moisture, and the pressure fluctuates with temperature. Why would anyone use air, and introduce moisture to a refrigeration circuit? Nitrogen costs money, so maybe it’s just being cheap.

You have helped me the most with ac

Got a question if the system has no refrigerate and evacuated the system could you use a smoke machine to find a leak

I had a very odd issue on my 83 Mark VI. A leak that only leaked when the ac was cooling
I vacuumed system it held vacuum for 24 hours, charged system and cooled great for 30 minutes then went warm, low Freon. Pulled out what was left in system with my ac machine and stored in recovery tank. Then rigged up a fitting for air line. Pressured up to 120 psi, held great 24 hours, retightened all lines to be sure. Recharge it with dye. Cooled good for 30 minutes. Found the dye dripping out of the ac box under dash .
So I replaced the evaporator core. It cured the problem

you don't like using refrigerant "sniffers" or at least for the hard to reach areas?

What if you use an water filter on your air compressor to remove most of the water in the air? That should be fairly harm free for the system or?

could I also confirm a leak by putting the system under a vacuum for about 45 min?

I will say your videos on ac troubleshooting and repair are the best anywhere. I’ve been quoted $3500 to start on ac fix. With your help I’m under $1000 with rear evaporator core, compressor, r-134, and vacuum pump and manifold gauge. Thank you for videos!

Thanks for the video. I added 2 cans of refrigerant and 2 days later, no AC. Now I know how to find the leak.

Great video, first one I've seen which makes this sort of work manageable for DIY mechanics. Can anyone recommend a way to make a test rig like he has in the video? Any links to products would be great :)

Using this method I found 2 leaks: 1 on the Evaporator-to-Expansion Valve bottom line. I think it was a wrong o-ring there, bcs after I put a thicker o-ring on that connection, the leak stopped. The 2nd leak was found on the body of the Compressor, on one of its seals, not central one, but the one closer to the end. My question is, if anything can be done about that compressor (it is pushing oil, if to rotate the clutch), or I need to replace it? This is my 1st work on car AC. I would really appreciate any opinions on this matter. Thank you for this wonderful film again.

What if the ac working but not so cold let’s say 65-70%?

I use Dawn Liquid Soap from the Dollar Store…A teaspoon makes a lot of bubbles!!

The vehicle was leaking to the point where the system was empty of refrigerant. I found and repaired the leaking expansion valve. I put the system under a vacuum for 45 minutes without issue. I decided to pressurize the empty system with 100 PSI of air. The system kept 100 PSI for three hours. I wanted to verify the compressor was functioning before recharging the system. I performed the test of starting the vehicle for a few seconds as demonstrated in this video. The low and high side gauges did not move. The compressor clutch engages and there are no leaks or abnormal sounds coming from it. Any other tests I can perform before assuming the compressor is bad?

good

I wish I had seen you pump air into the system before I wasted 5 cans of 134 looking for a leak in my house.

Great work

what are the symptoms of a comprssor run without refrigerant - low pressure - what sort of pressure should the compressor be delivering?

Could you do this test with a 4 port manifold? Just plug the discharge port?

Man first off just want to say thank you for your content and the information you share. I was able to find the leak on my wife’s 2011 Chevy traverse and replace the parts that needed to be replaced. The local shop wanted an arm and a leg for the work I was able to get done at the fraction of the cost by watching your videos and investing in a set of gauges and a vacuum pump. Thanks to y’all my wife’s SUV is ready for another hot summer in the high desert of CA.

I'm here because I was skeptical about using free compressed air. I hate wasting valuable freon to find a leak. I'm going to inject air but use a $3 disposable paint gun water filter as another person said. My customer's durango doesn't have a dryer can like older vehicles so I fear water contaminant.

Air has moisture. Even empty some trace refrigerant may still be in circuit. Moisture, poe, trace refrigerant HFC= ACID Hydro Flouric Acid. Explosion not so much, not under pressure but Acid isaproblem. Of course car compressor does not have internal motor winding to ge eat up, but it has rubber lines, aluminum. This is why we vacuum, to boil moisture away at very low pressure.

I have deep feelings for and about this one. It showed how to tell the compressor still works !!! when I'm and my beloved is coming from like situation of emptied system dry from leak ...right? Been left without working it sporadically to keep it I'm shape.
But mostly it determines compressor does function and I haven't hurt it.

As a tech i can tell you. For GM cars, always check your condenser 1st. They are notorious for Condenser leak.

Paul, it's hot until you move to Arizona and realize what hot is.😁

jesus is not god or son of god he never claimed it

Thanks for the video as I am dealing with this same issue. System held 83psi for over two hours so I believe I should not have a leak?? Thanks again.👍👍

I'm not sure if anyone else has made this comment, but a better method is using compressed nitrogen. Filter nitrogen will not introduce contamination into the system. Plus a higher pressure can be achieved. This is the way home/commercial air-conditioning repair is conducted. I use Big Blue Micro Leak detection soap.

super😊

Would the soup & water work even if there is no compressed air in the system?

Excellent video, great job, very, very, very professional.

Perfect video. Shop air is a great idea. No need to waste refrigerant and dye

I personally want to replace all major components tied to the A/C system. Period. A hot wife in the summer is Russian roulette fellas. Total cost $450 + Labor. Peace of mind, priceless...

Customer put couple cans refrigerant in? 😆 How many cans did the vehicle refrigerant sticker recommend? 😆 Good video. Careful using compressed air vs nitrogen. Water is a non-condensible.

Not problem to push a bit of shop air to find a leak provided the system is empty (the case here) and system pulled to vacuum for 30 mins after parts replaced to remove any residual moisture from the system having NO pressure for a long time and the shop air. All good.

Thanks for quick reply. Will check the Orifice tube and dryer parts. Have not used air con as you suggested. Bob

Have a UK spec Volvo V70 D3 Estate. My a/c compressor has a schrader type pressure valve that is now discharging 134a refrigerant. Compressor cuts in for a few seconds, discharges refrigerant and then cuts out. Could this be the high side pressure valve not working or something else

Powerful car A/C compressors will easily pump way over 200PSI (300PSI on the high side on a 4th gen Z28 Camaro on a real hot summer day for instance ... think AZ desert "loco" day), and you need to be able to check such pressures. Most of shop air that I know go 120 - 150PSI max, I haven't ever seen one going 300PSI.
I don't know ... nitrogen pressure test seams to be the acurate way to do the job, AND you don't further pollute the A/C system with air moisture.
You know of any shop air that goes 300PSI (brand, model) ???
By the way, you can weld together a 1/4" SAE adapter for A/C pressure testing.
Anyway, nice video! I discovered the channel lately, I really like it. 2 thumbs up!

Hello, I am trying to find a leak in my 1999 F230 super duty... can you tell me what fittings I need to buy to fill the AC system with air using gauges..(that I will purchase too) Thanks!

Professional, informative video! Many thanks from a long time shade tree mechanic!