[vmathews]

Good effort vigsom. It is a sad truth that many FNG's have turned into scam artists.

Now for some additional inputs on Car Air-cons from a (former) professional:
1. Very slow refrigerant leakage is expected to happen in a system where there are multiple bolted joints (split ac at home for example). This is due to the pressure and the fact that no bolted joint is perfect. In vehicles, vibration and engine heat add to accelerated leakage.

2. CTC (Carbon Tetrachloride) flushing is only recommended in case the unit is fully opened. However, I am not sure if CTC is acceptable or compatible with the modern Refrigerants and Air Con Lube

3. In case the Air Con is fully opened, please ensure that the Dryer / Accumulator is replaced. In any case, please replace once every 3 years or as per Manufacturer's instructions.

4. In case any joint is opened, please replace the O-Ring also. I noticed that there was no mention of O-Ring replacement in vigsom's article.

5. Most modern Air Con Lubes are susceptible to Adsorption (can attract and retain moisture in the air) and is a big No-No for any Ref & AC system. Always ensure that the Lube is filled in at the last (before charging the Refrigerant) and always from a sealed container.

6. The Oil Charged must be equal to the oil removed from the system. Please ensure that you do not overcharge the Lube. Car Air Cons do not have an Oil Sump like engines.

7. Before charging Oil / Refrigerant, ensure that the system is properly evacuated. Hold the Vacuum for about 30 minutes (if there is even a minor leak, the vacuum will drop).

8. Similarly, the Leak Test (also called Pressure Test) should be done using Nitrogen and above 200 PSI as the High / Discharge Pressure is well above 200 PSI during normal operation. Most garages will be happy with 100-150 PSI, please ask them to increase the test pressure. I assure you, no part will get damaged due to the test.

9. In case the Compressor Oil Seal fails, my recommendation would be to replace the compressor. Air Con compressors are not meant to be opened and serviced. Also, spares availability is always a big issue.

If anyone has any specific queries, please let me know.

[Fiestaboy]

Excellent write-up.

If we are totally addicted to our vehicles, undergo such repairs & got it corrected, then the relief or sleep that we get on that day can't be explained in words.

I had such an experience with my RX135 few years back & the amount of relief I felt when the issue is solved made me jump many times when i reached my home back. This thread took me to those moments.

[vigsom]

Originally Posted by Kosfactor

I would imagine the SOP for ASC will be to replace minimum condenser , evaporator, drier and a bill that would make a grown man weep.

A good AC mechanic is hard to come by, like a good auto electrician.

Thank You @Kosfactor, and you're right about the ASC typically recommending components replacement, especially the compressor and condenser as a pair after certain 1000s of kms have been clocked. IIRC, Toyota ASCs recommend this at approx. the 1,50,000km mark. Needless to mention, bills at ASCs for ACs are indeed steep.

Originally Posted by puneetakhouri

So my Baleno's ac has been leaking for a couple of years now and a topup would take care of it

Thank You, @puneetakhouri. Yes, even a friend's early 2018 Baleno that had just 18k kms on the clock lost refrigerant 4 months back. I read that there was an issue with the condenser in the earlier batches.

Originally Posted by ashpalio

My little electron muncher e2o has this slow AC gas leak, I have been topping the gas rather than get on a hunting expedition.

Thank You, @ashpalio. In hindsight, I think one would be better off topping refrigerant if the drop in charge happens, say, once in 9 months. The only downside is, environmentalists will raise a flag for this practice.

Originally Posted by Prasanth Nair

Reminds me of when I had a similar issue with my Toyota Prado

Thank You, @Prashant Nair. For me, older Toyotas eg.2000s are the benchmark for longevity. I've known Fortuners and Corollas that of that genre that still run on stock ACs. Surprised that you faced an issue with the Prado. Opening a dashboard is something I hate to do, and the thread is enough testimony to my statement. Surprises after installation can sometimes be nasty.

Originally Posted by vmathews

Now for some additional inputs on Car Air-cons from a (former) professional

Thank You, @vmathews. I've at last found a professional to certify all good practices. O rings are never changed by any AC technician that I've seen this far because they believe that the "company" ones are better. In their experience, they never leak.

Some professionally trained AC technicians from Kerala replace the receiver drier everytime the AC system is opened. A very good practice, I'd say.

The guy I went to wanted to use some thinner in the name of CTC and I just didn't like it. I don't recommend any cleaning agent (CTC was banned in industry several years ago), except perhaps IPA which has a low boiling point. However, the system should be closed only after the lines have been purged and are bone dry.

Originally Posted by Fiestaboy

If we are totally addicted to our vehicles, undergo such repairs & got it corrected, then the relief or sleep that we get on that day can't be explained in words

Thank You, @Fiestaboy. One of my weaknesses is my everlasting love for my machines, and that's why I never look at the clock when I've something to do on them. Sometimes I feel I should slow down or detach myself, but then, old habits die hard !

[scorpian]

@Vigsom
Whats your opinion over automated machines like manatec over manual gas charging?
I have a Sx4 2012 which has never had its ac worked upon, recently started seeing a drop in cooling and earlier the Cold line would start sweating immediately but now it sweats after a while.

I am more inclined towards doing it via machine since the quantity of gas charge would be perfect.

Whats your opinion on the same please do share.

Regards,
Manoj

[ankitsharma]

I have a 2015 Swift Dzire Diesel. The air con was never opened.
Recently on a short trip of 300 KM the AC cooling was bare minimum to call it cool. Dad informed that he had recharged the gas 2 years back.
I went to the same guy and he recharged the gas again for 500 bucks. On testing at the workshop itself the cooling was not what it used to cool when the car was 2-3 years old.
I think there is some leak in the system which eventually releases the gas in a span of ~2 years.
After going through your post looks like I will have to also test my air con for leakage. Specifically the coils.
Also I have found the MGP Ecstar evaporator cleaner very effective in cleaning the cooling coil. Costs around 1.3k but worth every penny specially for 5+ years older cars where the coil was never cleaned.

Originally Posted by scorpian

@Vigsom
Whats your opinion over automated machines like manatec over manual gas charging?
I have a Sx4 2012 which has never had its ac worked upon, recently started seeing a drop in cooling and earlier the Cold line would start sweating immediately but now it sweats after a while.

I am more inclined towards doing it via machine since the quantity of gas charge would be perfect.

Whats your opinion on the same please do share.

Regards,
Manoj

For ages the gas has been recharged in our cars manually. I never trusted that process. Last time during the recharge the oil was sucked in manually and the gas too. Results were not that great.
This time I went in for a machine refill. Believe me it is 1000 times better than the manual one. For one, the oil & gas quantity is perfect and can be measured on the gauge. Second, the process is very fast. I mean literal fast. It took only 5 minutes for my car to refill almost 400 gm of gas.
I initially did not believe that the gas was filled and thought that this guy might have taken me for a ride. Had an argument but then he demonstrated me how it works.

[vigsom]

Originally Posted by scorpian

Whats your opinion over automated machines like manatec over manual gas charging? I am more inclined towards doing it via machine since the quantity of gas charge would be perfect

Tough call, but I'd choose the machine only because one can charge exactly the recommended quantity of oil and refrigerant in.

The only demerit of the automated machine in India is - one can't be sure of the quality of refrigerant or oil that it holds as tbis may have been removed from many cars. Eg. refrigerant evacuated from car1 would be great quality eg. Chemours, but something from car2 might be poor quality eg. some cheap refrigerant that was charged by some run of the mill AC garage, and all this refrigerant would be a homogenous mix. Same logic with oil.

I have seen two garages, one in Gujarat and one in TN, that have the machines, yet charge fresh refrigerant via cans.

Originally Posted by ankitsharma

looks like I will have to also test my air con for leakage. Specifically the coils.

If the system is losing refrigerant, there is a leak. But I'd suggest you inspect the condenser for refrigerant oil stains, and the evaporator next. I'm surprised to see poor cooling even after a gas charge. I'd only suspect a fouled evaporator here.

Sample leaky condenser (image courtesy @puneetakhouri)

[ankitsharma]

Originally Posted by vigsom

If the system is losing refrigerant, there is a leak. But I'd suggest you inspect the condenser for refrigerant oil stains, and the evaporator next. I'm surprised to see poor cooling even after a gas charge. I'd only suspect a fouled evaporator here.

Sample leaky condenser (image courtesy @puneetakhouri)
Attachment 2197193

Yes this was the condition before filling the refrigerant.

[scorpian]

@vigsom
Luckily I have two spare r134a cans with me of reputed company.
I plan to do it in mass but using my cans of freon. I have also seen them using good cans of freon but they charge 4000 for gas evacuation and recharge with the machine.

My only issue is I don't have immediate cooling in my car, the cooling and sweating on low side starts after say a run of a km and then its cool to feel. Somehow I feel its low as earlier the minute I used to switch on the Ac the low pipe would sweat and even the compressor near the low pipe joint would sweat.

[R2D2]

@vigsom this is such an educative and informative thread. A real delight to read as are all your threads on automotive innards. It really is a treat. Thanks so much for sharing your experiences suggestions and of course those pictures. I'll certainly ask for your advice on an AC system repairs.

About your comments on the early 2K-'10 Toyotas being solid, I can attest to that. My Altis turns 13 in Oct '21 albeit very low mileage. It still hasn't required an AC gas top-up. They checked the system pressure and vent temperatures back in 2019 and it was still good to go over a decade after leaving the factory. Hey, "It's a Toyota"