Car Aircon service

[Onemore52]

The aircon in the Nissan snufffed it the other day, for whatever reason.

Is there more to just getting it regassed like one mechanic has offered to do?

TIA

[Rayj]

Last year, A friend had a failed Air con so he took it to my mechanic who tried finding the leak by adding colored gas then seeing where it came out of. After much effort he Never found the leak. then my friend just  added something called Stop Leak to his aircon refilled again with the refrigerant and it worked alright for the rest of the summer, over 2 months.

[Tommy T.]

5 hours ago, Onemore52 said:

Is there more to just getting it regassed like one mechanic has offered to do?

 

If it were me, the first step would mainly be sure to find a qualified mechanic with decent equipment. He will know what to do usually. Considering that I think most drivers run air/con most of the time, there are plenty of good specialists out there. If you trust him, then just let him do his job and don't read any more of my comments. I am a DIY guy so tend to get a bit more involved - maybe than I should!

The Stop Leak is another way to deal with it. However, because of how it works (by gumming up a hole or leak in a small gap) it can also ultimately reduce the life and efficiency of the air/con, so should be used with caution. If possible, I prefer to fix the problem rather than the symptoms.

These are the things I would look for and do for my car.

Have the mechanic put his gauges on the system to see if it still has gas. If so, then he can add more to spec. and check for air bubbles in the sightglass. If there are bubbles, then there is possibly a leak somewhere. In other countries, it is not too expensive to top off the gas. Then try the colouring leak checking. Check that the drive belt isn't slipping. It can also be that the compressor clutch is not working. If you run the engine at idle with the air/con off, then switch it on, the engine rpm will drop for a moment as it takes on the compressor load. Or you can visually see the pump part of the compressor turning with air/con on and not turning when air/con off. If there is little or no gas, there won't be so much load.

If nothing is found after recharging and it seems to run okay, you can then you can just drive around with it for a while and see if the problem returns - that's the cheapest way to go. It could be a very small leak that just needs a top up once a year or every six months? If the air/con is not used for a while, gas can sometimes leak out the compressor too.

You did not mention if this was a sudden thing or was it gradually not cooling as well over a period of time? And how old is the car with what mileage? If it has lost most or all of the gas quickly, then that sounds like a significant leak in the compressor, evaporator or the lines. The coloured gas testing is one way to possibly locate the leak.

It's more expensive, but a qualified mechanic should run a vacuum test on the system. They hook up and vacuum the system for a while, then shut that off and check their gauge to see if the vacuum level remains unchanged with the engine not running. If it shows loss of vacuum, then it's more complicated. I don't expect they have "sniffers" here? Does anyone know? If so, then, charging the system with gas and then using the sniffer, they can sometimes find the leak - or at least the vicinity of the leak.

However, if a leak is found and then fixed, they will need to vacuum the system before recharging. They will also need to change the dryer/filter before doing that.

There is also likely someone here with a lot more experience and knowledge than me. If so, I am sure they will reply here too.

Edited August 20, 2019 by Tommy T.

[Tommy T.]

12 hours ago, Onemore52 said:

Is there more to just getting it regassed like one mechanic has offered to do?

 

I forgot one other simple thing to check. Make sure the electric fans behind the radiator are both running. A lot of cars here use two electric fans up front - one for engine cooling and one for air/con. If you turn the air/con on and off, the fan should also switch on and off with it. I have had the A/C fan fail several times.

Edited August 20, 2019 by Tommy T.

[Mike J]

There is also the possibility that the AC compressor has stopped working for some reason.  Had this happen to my Chevrolet 71 pickup in the USA.  It was an expensive fix even when buying a rebuilt, instead of new, compressor and exchanging the core of the old one that had seized.   Or maybe a broken belt that drives the AC compressor?  That would actually be nice as it would be a relatively cheap fix.

[Dave Hounddriver]

55 minutes ago, Tommy T. said:

If it were me, the first step would mainly be sure to find a qualified mechanic with decent equipment.

Been there, done that.  He gave the system a cursory inspection and then told me: "We will try filling the freon first.  If it leaks fast we will work on it but the cheap fix is to add the freon and monitor it."

I am not sure if he added freon or if that was just the generic term for the gas he put in.  I am sure that the cost was only $20 and that it is still working fine a year and a half later.  Others have told me that car airconditioners are subjected to so much shaking around that it is easy to leak some gas over a long time.  If all I have to do is add "freon" once a year then that works for me.  Your mileage may vary.

[Onemore52]

Thanks everyone for the advice, which I appreciate this forum for, no bullshit.

TommyT, yes a new workshop has opened in town and from my first impressions he has all the good gear, off to him I go, after I sought out the latest water problem.

Cheers.

[LUFCinMakati]

6 hours ago, Tommy T. said:

If it were me, the first step would mainly be sure to find a qualified mechanic with decent equipment. He will know what to do usually. Considering that I think most drivers run air/con most of the time, there are plenty of good specialists out there. If you trust him, then just let him do his job and don't read any more of my comments. I am a DIY guy so tend to get a bit more involved - maybe than I should!

The Stop Leak is another way to deal with it. However, because of how it works (by gumming up a hole or leak in a small gap) it can also ultimately reduce the life and efficiency of the air/con, so should be used with caution. If possible, I prefer to fix the problem rather than the symptoms.

These are the things I would look for and do for my car.

Have the mechanic put his gauges on the system to see if it still has gas. If so, then he can add more to spec. and check for air bubbles in the sightglass. If there are bubbles, then there is possibly a leak somewhere. In other countries, it is not too expensive to top off the gas. Then try the colouring leak checking. Check that the drive belt isn't slipping. It can also be that the compressor clutch is not working. If you run the engine at idle with the air/con off, then switch it on, the engine rpm will drop for a moment as it takes on the compressor load. Or you can visually see the pump part of the compressor turning with air/con on and not turning when air/con off. If there is little or no gas, there won't be so much load.

If nothing is found after recharging and it seems to run okay, you can then you can just drive around with it for a while and see if the problem returns - that's the cheapest way to go. It could be a very small leak that just needs a top up once a year or every six months? If the air/con is not used for a while, gas can sometimes leak out the compressor too.

You did not mention if this was a sudden thing or was it gradually not cooling as well over a period of time? And how old is the car with what mileage? If it has lost most or all of the gas quickly, then that sounds like a significant leak in the compressor, evaporator or the lines. The coloured gas testing is one way to possibly locate the leak.

It's more expensive, but a qualified mechanic should run a vacuum test on the system. They hook up and vacuum the system for a while, then shut that off and check their gauge to see if the vacuum level remains unchanged with the engine not running. If it shows loss of vacuum, then it's more complicated. I don't expect they have "sniffers" here? Does anyone know? If so, then, charging the system with gas and then using the sniffer, they can sometimes find the leak - or at least the vicinity of the leak.

However, if a leak is found and then fixed, they will need to vacuum the system before recharging. They will also need to change the dryer/filter before doing that.

There is also likely someone here with a lot more experience and knowledge than me. If so, I am sure they will reply here too.

Spot on there.

 

Edited August 20, 2019 by LUFCinMakati

[Tommy T.]

1 hour ago, LUFCinMakati said:

Spot on there.

Thanks for sharing that LUFC.

I think that was a good video for the basic check and refrigerant refill with sealer. In refrigerant terms, the sealer is simply a lubricant that is included in every commercial gas supply - they all contain lubricant for the seals and compressor. And, yes, that can be the problem -  that they have dried out over time - that's normal with older systems.

However, a novice needs to be very careful to not tip that refill can too far either side or it could dump liquid coolant into the system - that's would be very bad. The instructions given in the video must be followed exactly regarding that tipping. And the can should not be shaken either during the re-charge.

A proper recharge hose connection from the can to the service port should include a bit of a bleed of the refrigerant from the can and fill the hose and spray a bit of it out. Otherwise you are introducing a bit of air into the system that was in the recharge hose - unless the kit has already purged it and filled it with a bit of the refrigerant. Any air in the system degrades it and contains moisture - which is also bad for the system.

The last thing should be to check the sight glass for bubbles. Maybe the technology has changed in the last 20 years? But formerly, there was a sight glass in line with one of the hoses where you can observe if there are any bubbles... Bubbles are also bad. I think it was located on the dryer/filter, but that's so long ago...

I hope this helps explain a bit further about the video...

Edited August 20, 2019 by Tommy T.

[Arizona Kid]

12 hours ago, Onemore52 said:

The aircon in the Nissan snufffed it the other day, for whatever reason.

Is there more to just getting it regassed like one mechanic has offered to do?

TIA

It really depends on how old the car is. If the car is old, so is the AC system. Ask a neighbor for somebody reliable? Had a 1994 Honda Accord that had problems till I found a guy that was honest and didn't charge me too much to get it running like it was brand new. Cost me the price of a new condenser, but after that it ran great for years.