Aircon Evaporator

[Ogben Schmutzel]

Appreciate it might depend on where the leak is but with a bit of ingenuity is it possible 1) to DIY pressure test it to find the source and, 2) repair it?

 

Any thoughts?

 

Regards.

Oggy.

[Guest 3.5bullet]

from my experience it's a full dash out job! ok if you have the time and the space under cover? the unit has plastic end caps which are not the easiest things to repair! and then to find a hole in the condensor and fix it well enough so that the repair will last? so you wont have to pull it all apart again? go for a new unit and sleep better at night :( or give the job to someone else to do and let them have the restless nights worrying while the works still under warrenty :(

[Masked Marauder]

I concur, it is dash out and a new unit if the old one has failed.

[Ogben Schmutzel]

Ok, I can do without the Alhambra for a few days so can take my time getting the dash out etc.

 

Trouble is I don't want to throw any more money at this problem, until I know for sure where/what it is and what my options are. This really means that I need to do the labour myself as the garage won't entertain holding on to a dismantled car while I think about it. Also don't want to pay their hourly rates for investigating because to date I have had 3 regasses and two leaks fixed in this car and it still leaks!!!

 

Appreciate there is a degree of risk with what I am proposing here but I only pay for the parts, and if I wanted to I even do a recharge with a can from Halfords!!

 

So with the dash out could I test the evaporator unit myself. I am thinking here of removing the evaporator, pressurising it somehow and putting under water or something to test??? There must be a way!!

 

Regards.

Oggy.

PS: Would take a photographic record!!!

[NikpV]

PS: Would take a photographic record!!!

 

that would be great cheers :( :(

[Gadgetoid]

I can confirm that to get to the evaporator you not only need to take out the dash, but a bit of the engine bay too :lol:

 

Unfortunately by the time you have got to the evaporator you've already incurred most of the expense - Ford quoted me

[MrT]

I was not aware of this tube in the bulkhead, but if I have a leak in my evaporator and I have UV dye in my system, will it be visible here?

[seatkid]

If I search hard enough.... :10:

[Gadgetoid]

I'm not sure about whether the UV dye would show up from the condensate drain tube - but I see no reason why not. It shows up well quite well in one of Nik's photo's in the link SK has added above - you can see it just below the bulkhead connectors on the picture of the extracted evaporator.

 

The sniffer tests for the fluorocarbons I think ( Aircon man told me it sniffs for nitrogen, but that doesn't make any sense at all )

[NikpV]

Aircon man told me it sniffs for nitrogen, but that doesn't make any sense at all

 

true too much nitrogen in the air, none at all in fluorocarbons

[Guest 3.5bullet]

most places fill the system with nitrogen under working pressure to check for leaks before they refill with the real gas!

[NikpV]

most place fill the system with nitrogen under working pressure to check that for leaks before they refill with the real gas!

 

 

but how could they distinguish between nitrogen in the air and nitrogen from the air-con - isotopic analysis?

[Gadgetoid]

That's exactly what I thought - and seeing they were sniffing the system when it was full of normal R134a fluorocarbon without any special nitogen fill I added 2+2 to the obvious answer :wacko:

[Guest 3.5bullet]

taken from http://www.chesterautos.co.uk/files/aircon.html

 

Identify system contents with refrigerant analyser

Recover all refrigerant from the system

Remove and replace the filter unit

Check condition of the condenser unit

Check condition of all hoses and wiring harnesses.

Check compressor oil level

Pressure test the system with dry Nitrogen

Vacuum system for a minimum of 30 minutes

Recharge with R134A refrigerant and oil

Leak test all components

Carry out pressure and temperature test.

Update service records.

 

and again at http://www.air-care-automotive.co.uk/FS1.asp

 

 

and the reason why nitrogen is used

 

The system is pumped up with nitrogen to operating pressure. Nitrogen is used as it is cheap and is safe to vent into the atmosphere. Once pumped, the system is left for ten minutes and the pressure monitored.

[NikpV]

your point being ?

 

 

the statement being questioned was the assertion that 'they were using a sniffer to detect nitrogen' not that they do pressure test with nitrogen

 

 

......( Aircon man told me it sniffs for nitrogen, but that doesn't make any sense at all )

 

how is this, albeit informative procedure, connected to this question?

[Guest 3.5bullet]

your point being ?

 

 

the statement being questioned was the assertion that 'they were using a sniffer to detect nitrogen' not that they do pressure test with nitrogen

 

 

......( Aircon man told me it sniffs for nitrogen, but that doesn't make any sense at all )

 

how is this, albeit informative procedure, connected to this question?

 

 

QUOTE

Aircon man told me it sniffs for nitrogen, but that doesn't make any sense at all

 

 

i answered the question as too why they use nitrogen, if you have problem with that please feel free to send me another pm

[NikpV]

The sniffer tests for the fluorocarbons I think ( Aircon man told me it sniffs for nitrogen, but that doesn't make any sense at all )

 

I don't think anybody has any query about pressure testing with nitrogen its been covered before many times, I was agreeing with gadgetoid's doubt about what the aircon man was telling him, nobody was questioning the usefulness of that wonderfully cheap inert gas formally known as azote. The point being that without some sort of isotopic analysis (expensive and fiddly in a garage environment) and some isotopically different (from the atmosphere) nitrogen it would be impossible to look for a leak by detecting the escaping nitrogen with a sniffer.

 

 

ps whats the point of another pm you have yet to respond to the first