Air con recharge -an enquiring mind

[Pipemaster]

Just had the air con recharged in the C Class the report showed that there was zero left to be emptied. The systems was pressure tested at just below 1 bar for 18 mins and then oiled and recharged. Now like Siberia all for 50 quid.
question is were did the old coolant go.

The system had no leaks - but does it slowly leak through seals over the years?

 

[BlackC55]

It MUST have a leak. The refrigerant does not just dissapear. Did they inject any dye into the system?

9/10 its the condensor leaking.

 

[Andy Wr]

1 bar / 14.7 psi is not enough, you need 1.5 times the maximum operating pressure of the system, 300 psi is a good amount to use with a trace of R134 so normal leak detection can be carried out, you have definately got a leak.

 

[Glenn Smith]

gas is lost over time, but to have no gas at all you either have a leak or someone let the gas out. Leak detection can be difficult, but the condensor will be my first place to look on the C class, usually between the rad and condensor, dye will show up only if you ease the two apart from the top and look down. Leaks can be tested for using vacuum and pressure, by addition of a dye (this won't tell if you have a leak, but will help pinpoint the position of a leak) there is also electronic leak detection devices, i have used these and not beeen very impressed giving false leaks etc.

 

[Pipemaster]

Thanks

OK so there's a leak we will have to get it looked at. Thanks for your comments all

 

[Uncle Benz]

Any aircon man worth his salt would have added dye in this situation, if only to make his job easier when you go back...

If the AC has not ever been touched before - many get no attention until they stop working - you may find it lasts for quite a while.

My aircon man has a Kia Sedona which has a slow leak. He says it lasts a year between top ups. He knows it is from the evaporator core in the dash. He also knows what a huge job it is to replace, so continues to top it up every year...

My only question is, how legal is it to knowingly continue to operate an AC system that has a leak?????

 

[Andy Wr]

My only question is, how legal is it to knowingly continue to operate an AC system that has a leak?????

It is classed as "knowling discharging refrigerant gas to atmosphere" illegal with penalties up to a £20,000 fine, there is supposed to be some big changes this year regarding who can purchase and handle gasses, we already know what we are not supposed to be doing with it, recharging a knowingly leaking system is one of them.

 

[tobro]

The answer to your original question is YES! Most vehicle aircon systems will leak some refrigerant over the years. The usual culprit is the compressor seal which is of the 'lip' type and requires to be lubricated (with compressor oil) to be effective. This can only occur if the system is run regularly and many systems leak in the UK through irregular use. I have emptied systems for bodyshops in the past where two year old cars have contained less than half their normal charge of refrigerant (probably through stockpiling at some stage in their history).

 

[Pipemaster]

The answer to your original question is YES! Most vehicle aircon systems will leak some refrigerant over the years. The usual culprit is the compressor seal which is of the 'lip' type and requires to be lubricated (with compressor oil) to be effective. This can only occur if the system is run regularly and many systems leak in the UK through irregular use. I have emptied systems for bodyshops in the past where two year old cars have contained less than half their normal charge of refrigerant (probably through stockpiling at some stage in their history).

Oh OK well it may be that there is no leak as such just that after 6 years of unknown levels of usage it didnt lubricate as much as it needed

 

[stats007]

I paid £25 at KwikFit for mine - recovered 385grams out of 875g from memory.

 

[pcman_jh]

Just tried one of those DIY rechargers from eBAY - so far so good

My '99 E300 TD had no cold air at all (last got any around Xmas). Took it to a Kwik Fit who ended up saying its coming up with a fault so gave me it back for no charge. (I'm not convinced how thorough they were as they were taking off side panels behind the nearside wheel and the front fog lamp access panel!!).

Anyway - Paid £30 for one of those pressure and charge cans on Ebay for £30 +P&P. On connecting it with the engine off, it was in the Yellow (higher than normal pressure) which means get it checked by a PRo. On starting the engine, as per the refill instructions, the pressure guage went to the Blue which means normal pressure. Gave it the whole can's contents, took about a minute, and now I have cold air.

Fingers crossed on how longs it lasts but I suspect it's the first recharge in the car's 8 year history!

 

[stats007]

Recharging doesn't recover any old gas or re-oil the system. You really need to do this properly.

The condensor fittings and evaporator sensor are usually behind those panels so don't see anything wrong in what they were doing?