Volvo Repair: 1995 VOLVO 850 GLE WAGON AIR CONDITIONING NOT WORKING, windshield washer fluid, volvo 850 gle

Question
Hello.  I bought this car used last year and after one month the air conditioning quit.  I waited until April this year to fix it, brought it to an auto a/c repair shop to get an estimate and they told me it would need shredder valve, looks like a small silver tube in front part of hood, near the windshield washer fluid tank as per the mechanic.  About 2 months later, it quit last weekend and I brought it back to the same shop, they said it might be another part gone wrong.  I was starting to wonder if they did a leak test which they insisted they did and if they did this test, it is puzzling why the air conditioning is not blowing cold air anymore almost 2 months later if supposedly they fixed the problem?   I also mentioned to them the unit goes on and off under the hood every second for the past half hour when I brought it to the shop and they said this is normal, but it never did that before and I know it goes on and off intermittently, but not every second.  What could be wrong that my air conditioning system is not blowing cold air?  And if they did a leak test and found the leak, why would the air conditioning quit almost 2 months later and they said it may be a different part?  Does Volvo cars have the same type of a/c parts like other cars?  I was looking at a picture of a/c parts in a car and they don't look like the Volvos. Thank you for your help.

Answer
Irene, Those shrader valves have leaked in the past but more than likely what is leaking is the Evaporator.  That is a common problem with the 850's.  The unfortunate part is that it is very labor intensive to replace that part.  The whole dashboard has to come out.  Be prepared to pay about 1000 dollars to repair that.  2 Months tells me that it is a slow leak.  If it was leaking bad it would only be a matter of days.  What they should have done is added a special dye to the system and then have you come back and use the special light to diagnose it properly.  I suggest a Volvo Specialist shop.  All Volvo cars have similar A/c systems but not all have the same parts.  That normal statement is incorrect. It is low on Refrigerant again.  Roger