A/C Leak Sealants

[Arv]

Hi Everybody:

Came accross this article and thought I will seek your opinions/experiences
with these products.

http://www.aircondition.com/knowledge_base/LeakSealers.html

I have used radiator/cooling system sealants before and they have
worked well. Only thing is that, after you put them in the antifreeze, you
MUST give about an hour or more of drive to the car immediately so the
leak seals properly.

Has anyone used any a/c leak sealants and do they work well?

Thanks a lot,
Arv.

 

[Arv]

Hi All:

Has anyone used any of these sealants? Any opinions are appreciated.

Thanks,
Arv.

 

[entropymatters]

I was going to try some. Now I'm waiting to see what response you get. Interesting in your link that 1 in 6 cars with an AC problem are Mercedes. I spoke to my indie yesterday about using a sealant (to save on a £400 replacement condensor) and he said that if I did, he would not then be able to use his vacuum machine to extract any old gas/fluid, because it knackers the equipment.

 

[carabind]

wonder what would happen if you hadn't have told them ?

 

[television]

wonder what would happen if you hadn't have told them ?

It would have knackered their equipment


Malcolm

 

[Andy Wr]

wonder what would happen if you hadn't have told them ?

We would of known once the vac pump or reclaim machine clogs and then the customer would have to pay to replace or repair them, mine cost £990. We have already received technical information warning us to be careful when reclaiming gas or vaccing out, we have to warn the customer that if it does contain that horrible gunge then he is responsible for any damage caused, second hand car dealers are already buying leak sealer by the truck load as it is cheaper than replacing condensers and shaft seals, its going to cause some big problems............

 

[jibcl500]

Dont mess about with AC systems, give it to MB or a specialist to sort out, the AC fluid used today R134 etc is nasty stuff, Ive tried these quick fix cans that plug into the AC system, made it worse if anything.

jib

 

[Andy Wr]

Anyone thought how it is going to affect the service ports where we attach our diagnostic gauges? The ports will set hard so that it will be impossible to use the ports meaning replacement valves if they can be removed from the pipe or complete pipe assemblies costing £££££'s, I am in the trade and I would certainly not put it in any of my 3 vehicles with air con.

 

[Braveheart]

There is only one acceptible component that should be in any air conditioning system. The required amount of refrigerant gas, normally R134A which is a relatively non-toxic refrigerant (environmentally green) weighed in to match the system capacity for heat transfer. It is in liquid state in the condenser unit, once sub-cooled, and flashes to a vapour state once introduced to the evaporator heat exchanger often across a pressure drop, like an expansion device or just a capillary if its a simple system. Sensible heat from the air flow ducting system is absorbed by the refrigerant vapour as latent heat of evaporation takes place in the cooler. Heat exchange to atmosphere takes place at the condenser.
There should be no leaks, no moisture, (as this causes ice pellets forming in the system and blockage) and no other elements, IF you want it to perform properly and efficiently and to original design intent. All heat exchangers should be kept clean and dust free to help heat exchange, especially in high ambient conditions. I would NEVER advise anybody to introduce any other element into the system, regardless of claims. Small amounts of refrigerant oil may be present, depending on type of compressor and year of manufacture, which is acceptible, it just travels around the system under vapour pressure velocity. The best way to keep clear of leaky systems is to keep heat exchangers clean whereby high system head pressures are not created.

 

[carabind]

It would have knackered their equipment


Sorru should have been more specific - I meant what comeback would the dealer have on the customer. since A/C got more common ten year ago, I bet there may be some of this gunk around in second hand cars, poor old owner number 3 or 4 goes for a purge and gas up and gets a far larger bill that expected (ie has to pay for the garage equipment !! Probably worth more than the car
My take would be that I thought I was "using " their kit , rather than replacing it for them!

 

[50sflash]

We check every a/c system with an analyser prior to connecting our equipment, If we find the system has any gas or additive other than R134a we do not get involved unless we evacuate the system into a waste tank using the correct machine, then flushing the system, rectifying any leaks by replacing with what ever new components are needed, This can be very expensive, my advise is do not use anything other than the correct gas R134a. John

 

[entropymatters]

The indie also said that my car (E320 Cdi) was not the first condensor problem that he had seen. Because the condensor is situated in front of the radiator, it bears the brunt of any old rubbish flying up from the road. There also seem to be issues with the bottom weld rusting away or giving way under the pressure of the system (which would not be fixed by a sealant, because the sealant fixes the hole and pushes the crack on further).:-?

 

[Arv]

Some good thoughts were put forth by you all. My problem is I am
not able to find the leak which is very very small. Last time I had
charged the a/c after putting in new receiver/drier, the shop which
did it put the system under vacuum to see if it is leaking and the system
help the vacuum pressure for I think an hour. Then I also went to a guy
with a ion tester to see if he detects some leak, but nada. But I know
for fact the a/c leaks in about a month. I don't want to start replacing
things that are not broken without a firm diagnosis.

Thank you for all the replies,
Arv.

 

[Blobcat]

Over here AC specialists put a dye in with the gas, they then go looking for the leaks with a UV (Black Light) lamp. I don't know if they do that over with you but it is worth a go.

 

[television]

As Blobcat really,if you want any details of the dyes used here,just ask.

Malcolm

 

[Braveheart]

Some good thoughts were put forth by you all. My problem is I am
not able to find the leak which is very very small. Last time I had
charged the a/c after putting in new receiver/drier, the shop which
did it put the system under vacuum to see if it is leaking and the system
help the vacuum pressure for I think an hour. Then I also went to a guy
with a ion tester to see if he detects some leak, but nada. But I know
for fact the a/c leaks in about a month. I don't want to start replacing
things that are not broken without a firm diagnosis.

Thank you for all the replies,
Arv.

I'm putting my money on the filter drier you had changed, by the "shop".
Flared refrigeration connections are renowned for leaking, especially if over-tightened. IMHO an hour is not really a good test for system integrity under deep vacuum, whilst I appreciate you can't stand around for hours on end waiting for a result. Also from experience I know that refrig systems can show no leak under vacuum, but leak under pressure, especially once "warmed" up, expansion etc......a good sniffer will pick up 2 ppm of gas.
Shouldn't be that difficult to find, have a good look (sniff) around the filter drier joints, then go back to the "shop".