air conditioning compressor

[grisley]

hi guys i have just found out in a service to my air conditioning that although there are no leaks and no gas  in the system, i have been told the compressor is not working, I can get a new compressor and possibly fit it. but being an unknown and the fact it states in the Haynes book to get a qualified technician to evacuate the system, does this in fact mean i can do the job or should i give it to a technician to do, i have been quoted Ã,£567.00 parts and labour./ or can i just carry on without doing the job, ie; would any damage be done if left as it is?  any help would be a advantage, thank you in advance.

[insanitybeard]

Whatever happens you'll have to pay a third party somewhere along the line, if there is no gas in the system presently then you could change the compressor yourself and just pay somebody to regas it for you which will save some money. Looking at it's location on the TDI, I don't think the compressor is that bad to change, however, at least on my 130ps TDI the retaining bolt for one of the pipes into the compressor is covered by a coolant pipe making it inacessible, I think the compressor would need to be unbolted and moved slightly so the bolt could be removed, or you would have to drain the coolant and move the coolant pipe, which is hassle in my opinion. If you do tackle the job yourself, don't forget to renew the O-rings on the 2 pipes leading into the compressor!

Also, if there are no leaks in the system then why is there no gas in it?!

[Chrispb]

Hi Grisley

So you have no leaks but no gas in the system, so have you had the system pressure tested then? the compressor will not attempt to work (for safety) if there's no pressure in the system.
A new compressor prices vary around Ã,£300-Ã,£400 so estimate probably not far out.
Changing it over is fairly easy if you need to change it yourself make sure you have new O rings for the pipe connectors.

Am a little concerned that you been told you have no leaks but there's no gas as these systems are prone to leaks so you need to be sure there arn't any before a regass.

I see your also from Chatham, I have used a guy from Bearsted for a few years he is mobile so works at your home, I've found him very knowledgeable and professional and recommend him to my friends and family

If you would like him to give you a second opinion or ask his advice his names Steve and trades as "Keep Kool" and his number is, 07960 869688.

[Mirez]

Before you do anything you need to confirm why they are saying the compressor is dead - as Chris has pointed out, if there is no gas in the system the compressor should NOT be working. Unless they have re-gassed it and then declared its not working I would be somewhat surprised if it has failed and its one of the more reliable parts of the A/C system. Who "serviced" it and what exactly did the service entail?

[steveo59]

Hi Grisley,
On airconditioning systems they have a pressure switch which is operated by the pressure of the refrigerant in the system. If there is insufficient pressure because of low or no gas, then the switch does not make contact so electrical voltage is not sent to the electro magnet that operates the clutch mechanism on the front of the aircon pump. This is to protect the pump by preventing the pump being driven when there is insufficient gas in the system. Hence your pump at the moment should not be working. However it is possible to connect a direct 12V to this connection so that you can check the operation of the clutch. You can do this without the engine running and you will hear a loud clicking noise as the aircon clutch engages. I am unsure as to whether or not it is advisable to run it with the engine on, just for a very short while, to check that the pump has not seized, because as well as refrigerant gas in the system there is also a small quantity of oil to lubricate the system, and I would  hate you to damage a good pump by trying it. Even if the pump does turn over you would still not know if it is creating sufficient pressure, which begs the question, How does the garage know the pump is faulty without running it? If they say there are no leaks then I would suggest checking the operation of the clutch and then regassing.  However should you need a new aircon pump I would suggest sourcing a used item from these VW spares specialists     http://www.stevensvwspares.com/vw-air-con-pump   

[gregers]

and if it is the compressor,i have 1 minus the clutch plate if your interested?even if you just want to try it etc to see if yours in fubared you are more then welcome.