Air con help!

Post your Cit/Peu/Ren air conditioning queries or advice.

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davetherave
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Joined: 01 Apr 2009, 21:06

Post by davetherave » 22 May 2009, 21:42

Looking around 25 quid definatly seems the cheapest! THink ill buy it and jsut hope that nothing else goes wrong, are there any other components know to fail such as the sensor or expansion valve? I can see my whole car being replaced in pieces here!

addo
Sara Watson's Stalker
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Joined: 19 Aug 2008, 12:38
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Post by addo » 22 May 2009, 22:43

What brand? IIRC the originals were made for PSA by Parker.

If you badly neglect an aircon, the condenser can corrode from internal moisture, but this will usually happen when the system is cracked then left open.

Evaporators corrode on some cars - such as XMs - but I'd suggest it's not too likely. Flex hoses can fail over time.

cachaciero
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Joined: 13 Apr 2009, 07:24
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Post by cachaciero » 26 May 2009, 17:38

admiral51 wrote:
davetherave wrote:Fair point, they did tell me that they took all gas out with a vacuum then put new in would this have taken the water out?
Not 100% sure but reckon if the dryer is full a vacuum wont remove it :( :(

Im pretty sure i have a reciever/dryer in the Xantia Spares Depts(shed/loft) that you are welcome to have if thats any help

Colin
It will have removed a little water from the drier but not much, but if the drier has a significant moisture content you have bigger troubles than that. The real problem with any system running R134A is the oil which is intensely hygroscopic and will soak up any moisture like it's going out of fashion.
As far as I can see from all that I Have read on this subject even application of a deep vacuum for 24 hrs is not enough to remove all the absorbed moisture and the only reliable way to get a clean system is to drain the oil purge the system and put in new oil at the same time as the system is gassed (having fitted a new drier).

If the system is run with oil containing moisture there is a reaction with the gas which produces acid which will rot out the evaporator and condensers from the inside sooner or later depending on the amount of moisture duty cycles etc.

If the system has never been broken down and still has some gas in it at a positive pressure then a procedure of extracting the remaining gas applying a vacuum and recharging should work o.k in fact it is the only really correct method for re-charging the system, of course for this to work on an automatic machine it does depend on the operator checking that the charging valves are clean and not corroded and that the charging hoses are correctly connected. The whole process requires an attention to detail which your average exhaust fitter is may not have.

I have successfully restored driers by putting them in the oven at about 150 degrees then blanking one end and sucking them down to a couple of millibars with a vac pump, then once cool charge with refrigeration grade butane (allows one to get the other blanking cap on before all the butane boils off!!) which was all I had to hand but dry Nitrogen would be better.


Cachaciero

DoubleChevron
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Joined: 22 Sep 2003, 18:06

Post by DoubleChevron » 10 Jun 2009, 06:17

You guys are just guessing until you can get some guages onto that system. If the center of the compressor refuses to pin... Does the clutch have power ?? If so, yep the compressor clutch is dead. If not, I find it more likely the system has leaked it's refrigerant out.

You MUST change the receiver drier, it won't stop the car cooling, but it contains a desicant that absorbs moisture. I'd be vacum'ing it down to see if it'll hold a vacuum overnight... If so, change the R/D and vacuum it down on a nice hot day for a few hours, then dump a charge in and see how it goes (or how long it takes to leak back out). If you don't have a vacuum pump and a gauge set, your wasting your time even looking at the air-con systems. :(

seeya,
Shane L.