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[Entwood]

Hi

Air Con / Climate will not run cold, compressor is spinning fine, and so are cooling fans.

Had it re-gassed this morning - they said it was not really needed as it was "almost full" - they took 750 grams out .. if that makes sense to anyone ?

Feeling the pipes in the engine bay, thin one from compressor is VERY hot, thick one is quite warm - I can keep my hand on it easily. I thought the air con pipes should run cold

Anyone any ideas what to check next ??

[Timbuk]

Yes they should be cold, i would be taking it back

[HGV mechanic]

not to sure if the compressor has a dog clutch :-?

this could be at fault,

but as timbuk says they should be cold

[Kevin Wood]

The one from the compressor to the condensor should get warm. The one from the bulkhead back to the compressor should be stone cold.

Just realised mine does Bu66er all too. Low-side pressure looks OK so it's still got some charge.  

Did they check the high / low side pressures once it was gassed?

If they took 750 grams of refrigerant out it was a little low but not a disaster. System should hold 950 grams IIRC.

Kevin

[Entwood]

The one from the compressor to the condensor should get warm. The one from the bulkhead back to the compressor should be stone cold.

Just realised mine does Bu66er all too. Low-side pressure looks OK so it's still got some charge.  

Did they check the high / low side pressures once it was gassed?

If they took 750 grams of refrigerant out it was a little low but not a disaster. System should hold 950 grams IIRC.

Kevin

Thanks for that .. I've no idea .. but I will be asking ..

[Kevin Wood]

Thanks for that .. I've no idea .. but I will be asking ..

Presumably they've vacuumed it out, checked for leaks and put the correct amount of refrigerant in. The next step should have been to verify that it's cooling properly, and, if not, measure the pressures. This will tell you if the refrigerant is circulating properly. Normally you should have a high pressure at the output of the pump and a low pressure at the input.

If the pressure differential is not great it means either the pump is fubar and not able to achieve enough pressure at the output or the expansion valve is not doing its' job. If the pressure differential is huge, it could mean the system is iced up due to moisture, blocked, etc.

Kevin

[Matchless]

If the compressor output pipe (to condensor) is too hot to touch then there is a blockage in the system.

DO NOT RUN ENGINE WITH A/C TURNED ON  you will kill the compressor (if it isnt already dead)

A blockage on the high pressure side can be difficult to find, it might be due to moisture in the system which freezes on the expansion valve (in the cabin) and blocks the refrigerant flow. It could be the receiver drier has broken up and let dessicant out into the system. It could be residue from an earlier compressor failure.
Either disconnect the compressor and forget about it or take it back to you a/c guys and open your wallet.