Air Con. Common points of leakage.
Discussion
Only just got my Cerb but the Air Con is not functioning. I have a friend who is a Air Conditioning Engineer and i myself have had a fair bit of experience working with Air Con in the past so i popped over to his so we could gas it up. Once i connected the guage's i found the system to be empty and on pressure testing it i found it to be leaking from somewhere. The big question is WHERE? The system was purged with OFN (oxygen free nitrogen) and the pressure steadily dropping and i sprayed every joint i could find with leak detector spray but still no joy. I'm suspecting a leaky condensar rad being as its right at the front and is susceptible to stones hitting it. My next step is to use a UV leak detector system but first i thought i'd check if anyone else has had a air con leak? If so where was yours and i'll check there on mine.
My air con has always leaked the gas, but could never find the leak even with a UV indicator to highlight the problem area.
In the end I was recommended an air-con sealant product that guaranteed to repair any leak and was added to the system the same way as the gas. It worked a treat and now I have cold air on tap!
Cost was a re-gas plus this can of sealant at an extra £55.
In the end I was recommended an air-con sealant product that guaranteed to repair any leak and was added to the system the same way as the gas. It worked a treat and now I have cold air on tap!
Cost was a re-gas plus this can of sealant at an extra £55.
Well its not long since had a re-con rad on it so if its got to come out it will be a little annoying. But i guess that's life..... I didn't get chance to test the receiver bottle as the screws to remove the access panel would not come out. Will drill out and replace them this weekend. The sealant idea sounds interesting if a little bit of an easy way out. I wouldn't have thought it would work but after seeing you testimonial at least i have a back up plan. I'd like to find the source of the leak but just in case do you know where to get this sealant kit from?
I'm another one from the refrigeration background.
If there's no sign of a broken pipe then the obvious place that it'd leak is on the shaft that drives the compressor.
As you know this seal works best when it's is in continuous use and there is oil moving around it.
During the winter months it'll probably never get used and the seal dries due to a combination of no oil on it and the heat in the engine bay of the Cerb.
Once you put the gauges on and start the compressor you'll find that there's no gas and by the time you've recharged it the seal will basically have "fixed" itself.
In theory it shouldn't leak there but in reality it does.
I reckon this would fall into the "unavoidable loss of refrigerant" category in the refrigerant handling legal jargon.
Hope this helps you some bit.
If there's no sign of a broken pipe then the obvious place that it'd leak is on the shaft that drives the compressor.
As you know this seal works best when it's is in continuous use and there is oil moving around it.
During the winter months it'll probably never get used and the seal dries due to a combination of no oil on it and the heat in the engine bay of the Cerb.
Once you put the gauges on and start the compressor you'll find that there's no gas and by the time you've recharged it the seal will basically have "fixed" itself.
In theory it shouldn't leak there but in reality it does.
I reckon this would fall into the "unavoidable loss of refrigerant" category in the refrigerant handling legal jargon.
Hope this helps you some bit.
Thanks for that. When i purged it with the OFN i ran the compressor to make sure the clutch was coming in and that the system itself actually worked i.e. High and low pressure sensors and also to try and circulate any oil in the system around the seals but afterwards it was leaking just as much and to be honest it was leaking a little too much to be a dried out seal IMO. The 134a is made up of alot smaller molecules than the nitrogen. I've heard them refer'd to as golf balls and grains of sand so if its going to leak with nitrogen the 134a has no chance. I do also believe that the reason alot of air con systems on cars stop working due to lack of use/dried out seals leaking out refrigerant. The vibration the system is subjected to dosent help either. I thought the "unavoidable loss of refrigerant" was refering to the refrigerant left in the pipes and guage's that gets released when you charge a system and remove them?
With respect it is the other way round - R134 is a much larger molecule than nitrogen.
A nitrogen molecule is N2 that is 2 atoms of nitrogen, molecular mass 14 and kinetic radius of aproximately 3.14 pico meters
R134 is C2H2F4 i.e. 2 Carbon, 2 Hydrogen and 4 Flourine, molecular mass 102 and a kinetic radius of 340 pico meters
ie R134 is around 100 times larger than Nitrogen
A nitrogen molecule is N2 that is 2 atoms of nitrogen, molecular mass 14 and kinetic radius of aproximately 3.14 pico meters
R134 is C2H2F4 i.e. 2 Carbon, 2 Hydrogen and 4 Flourine, molecular mass 102 and a kinetic radius of 340 pico meters
ie R134 is around 100 times larger than Nitrogen
Well thank you for correcting me. I would say that i'd probably not been paying attention in class and got that part wrong, but i distinctly remember the lecturer telling us it was that way round and me thinking why use nitrogen if there was possibility of it leaking with 134? I'm sure he said something about Helium being ideal but too expensive to leak test? My friend was on the same course as me so i will ask him what we were told tomorrow and correct him if need be also. You learn something every day. Anyway i'm still stuck with a leaking air con system. I'm going to test the reciever and joints at the weekend. Failing that i'll have to get it UV leak tested and failing that i may try that sealent stuff.
Guy J Russell said:
..... I thought the "unavoidable loss of refrigerant" was refering to the refrigerant left in the pipes and guage's that gets released when you charge a system and remove them?
It is.I was just dreaming up a "defence" for you with the environmental inspectors.
BTW I'd like to know a bit more about this sealant stuff.
Let me know where you get it and how you get on if you use it.
Guy J Russell said:
Well thank you for correcting me. I would say that i'd probably not been paying attention in class and got that part wrong, but i distinctly remember the lecturer telling us it was that way round and me thinking why use nitrogen if there was possibility of it leaking with 134? I'm sure he said something about Helium being ideal but too expensive to leak test? My friend was on the same course as me so i will ask him what we were told tomorrow and correct him if need be also. You learn something every day. Anyway i'm still stuck with a leaking air con system. I'm going to test the reciever and joints at the weekend. Failing that i'll have to get it UV leak tested and failing that i may try that sealent stuff.
Helium is significantly smaller than nitrogen, so I guess that the idea is that if a system will hold nitrogen then you can be sure that it will hold R134 without any problem.Try the leak sealer - it worked a treat on mine which has now been ice cold for a year.
Good luck
Ireland said:
Guy J Russell said:
..... I thought the "unavoidable loss of refrigerant" was referring to the refrigerant left in the pipes and gauge's that gets released when you charge a system and remove them?
It is.I was just dreaming up a "defence" for you with the environmental inspectors.
BTW I'd like to know a bit more about this sealant stuff.
Let me know where you get it and how you get on if you use it.
Tanguero said:
With respect it is the other way round - R134 is a much larger molecule than nitrogen.
A nitrogen molecule is N2 that is 2 atoms of nitrogen, molecular mass 14 and kinetic radius of aproximately 3.14 pico meters
R134 is C2H2F4 i.e. 2 Carbon, 2 Hydrogen and 4 Flourine, molecular mass 102 and a kinetic radius of 340 pico meters
ie R134 is around 100 times larger than Nitrogen
Tsstt!! As if we didn't know that A nitrogen molecule is N2 that is 2 atoms of nitrogen, molecular mass 14 and kinetic radius of aproximately 3.14 pico meters
R134 is C2H2F4 i.e. 2 Carbon, 2 Hydrogen and 4 Flourine, molecular mass 102 and a kinetic radius of 340 pico meters
ie R134 is around 100 times larger than Nitrogen
Guy J Russell said:
Tanguero said:
Try the leak sealer - it worked a treat on mine which has now been ice cold for a year.
Good luck
What sealant did you use on yours and where did you get it from? Can there really be such an easy and effective cure?Good luck
http://cgi.ebay.co.uk/AIRCO-SEAL-PRO-PROFESSIONAL-...
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