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Old 25th July 2019, 11:10   #1
Lambo
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Default Air con hot pipe

Hi Peeps,

New on here, just had my 04 ZT CDTI to the garage for a re-gass and after it was gassed up one of the pipes was red hot so mechanic dumped gas back out for safety says there is a problem but will have to ask someone who knows more about A/C systems.
Anyone any ideas?

Cheers

Ray
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Old 25th July 2019, 11:29   #2
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Of course it was hot. It is supposed to be hot. One pipe is hot, the other is cold and dripping with condensation this weather.
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Old 25th July 2019, 11:58   #3
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Look at the aircon system as a heat pump. The heat contained in the incoming airflow is transferred to the 'gas' via the evaporator in the cab, so the air is chilled. The heat it contained is pumped away to the condenser, where the fan transfers it back to the atmosphere. It's a loop, hot on one side and cold on the other. To operate correctly, the amount of gas present has to be correct otherwise things can get out of balance and overheating/over-pressurisation can occur. An aircon specialist will check weights and pressures to ensure it's right.



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Old 25th July 2019, 13:39   #4
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Thanks,
Guess I should have gone to an Air con specialist instead of a race mechanic!
Will go to the right shop.
Cheers
Lambo
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Old 25th July 2019, 14:32   #5
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To operate correctly, the aircon system must operate in conjunction with the radiator fan. It's essential therefore that the low speed fan is tripped on when the aircon starts. The simplest way to test the fan is to run the 'Demist Test'. Use the search box at the top of the page to find the instructions, they're posted all the time.


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Old 27th July 2019, 16:32   #6
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Quote:
Originally Posted by Lambo View Post
Hi Peeps,

New on here, just had my 04 ZT CDTI to the garage for a re-gass and after it was gassed up one of the pipes was red hot so mechanic dumped gas back out for safety says there is a problem but will have to ask someone who knows more about A/C systems.
Anyone any ideas?

Cheers

Ray
I am sorry to be difficult, but what exactly did your mechanic do, in this 're-gas' service, it would appear he has little to no understanding of the A/C system he is working on, my advice is go elsewhere, a specialist mobile proper A/C engineer, your cars A/C system needs several things doing to it before re-gas, I won't go into it, look up the posts on this matter of a very wise member here called Jules, it will all be revealed. The temperature of the two pipes in the A/C system is critical for correct operation of the system as well as safety, red hot means exactly what, do we have an actual figure, what about the other pipe ice cold?. Good luck.
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Old 27th July 2019, 19:59   #7
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Looked at Ray's car today it's in beautiful condition.

The problem with the Aircon is definitely the cooling fan, it's a 3 speed unit with only the high speed working .

That's why the Aircon pipe was getting hotter than it should have been

Russ
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Old 27th July 2019, 20:08   #8
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I've recently looked online for a MACS course. The mechanic shouldn't touch the a/c system unless qualified.
It's only a one day course and I'm weighing up whether or not to put myself on it. But at over £200 it's a bit minty.
Point being, the mechanic would've had to understand pressures etc. in order to qualify, and it sounds like your's didn't
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Old 27th July 2019, 20:48   #9
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The MAC5 was replaced in Jan 2015 by new f-gas legislation 517/2014 , contact the IMI or ABC awards if you want to get certified to recover refrigerant.
Repairing or replacing A/C components can be done by anyone but it does help having the "service technician" and "diagnostic technician" qualifications too.
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Old 28th July 2019, 09:26   #10
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Quote:
Originally Posted by BigRuss View Post
Looked at Ray's car today it's in beautiful condition.

The problem with the Aircon is definitely the cooling fan, it's a 3 speed unit with only the high speed working .

That's why the Aircon pipe was getting hotter than it should have been

Russ
There you have it a quick diagnosis of the problem the fan needs attention, yet the mechanic didn't seem to know that.!!
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