96 850 A/C condensor question

Post by **JimBee** » 24 Jun 2016, 14:07

Last summer I had a local shop recharge my A/C. It lasted for a month then lost pressure. I think they overcharged it b/c all the seals have green dye around them, there's even some dye near the front of the compressor. I assume those seals blew out which would account for the 0 pressure now in the system But how can I tell if the condenser was also damaged? If I have a vacuum purge I'm sure it won't hold a vacuum but I won't necessarily know whether the condenser is leaking. That would be good to know so I can decide if I want to refurb the system.

Is there a way to determine that?

Post by **scot850** » 24 Jun 2016, 16:46

You have the same dilemma I have for my 97 850. The only way I know is to have a good A/C shop see if the system will pull a vacuum. The fact you have dye at various connections, you would possibly have to replace those first (they are probably over 20 years old and hard. Use Volvo seals unless someone can recommend another good brand.

What you need to worry about is the evaporator in the cooling system in the dashboard. That is a pain to replace and also likely to have failed at this age. If you want to try an resurrect the system I'd replace the seals I can see first and then have the system pull a vacuum, re-fill with dye and A/C refrigerant, and then look to see where it leaks again.

Neil.

Post by **Ozark Lee** » 24 Jun 2016, 16:54

The places where you can see the UV dye are the places where you have or, at some time, had a leak. The exception to that rule, which can make things difficult since it is a point where a leak often occurs, is the Schrader valve on the low pressure port. Since that is where the dye is introduced to the system there is always some residual dye on the connector but the valve itself can and often does leak.

Condenser coil leaks are not common unless the car has been in a collision and that is about the last place I look. The evaporator coil and the accumulator are much more common sources. If the system has no pressure you can use an air compressor and a soap solution to try to find the leaks. The air compressor will introduce moisture into the system but if it is flat then it is already moisture laden and it will need to have the accumulator replaced and a vacuum pulled prior to recharging it anyway. If the leak is bad enough you can actually hear it if you get some compressed air in the system.

...Lee

Post by **abscate** » 24 Jun 2016, 17:18

Pull a vacuum and see if it holds vacuum. Very few leaks only leak one way.

A good shop won't recharge ypu without testing for leaks first. Losing charge in one month is a big leak. You can check the evaporator if you remove the fan and look in with a mirror or borescope

Post by **JimBee** » 24 Jun 2016, 18:41

Good suggestions, all. I think I'll first replace the o-rings where I know there was dye. The dye that was visible when the system went down is barely visible now, but I recall that all the points of connection where there's an 0-ring had dye around them. including the pipe at the back of the compressor. The one that worries me the most was the dye around the front of the compressor, behind the pulley.

With new o-rings installed, then I'll try to pull a vacuum.

TWO questions:
How much air pressure can safely be put in the A/C system?
Is the Schraeder valve the standard tire type?

Post by **Ozark Lee** » 24 Jun 2016, 19:28

A typical compressor will max out at 125 PSI which is well within the design spec for the system. A cup with some dish soap and a small brush can be helpful as well. Just brush the soap solution on the suspected leaks and see if it blows a bubble.

The Schrader valve is like a tire valve but it is a bit larger. They auto parts stores usually have a tray with various sizes and they can match it up for you. A tire sized core removal tool is too small but again, the auto parts stores have the larger tools. I think one I got has a small end and a large end both on the same tool and it was only a few dollars.

...Lee

Post by **JimBee** » 25 Jun 2016, 07:36

The dish soap idea sounds like a helpful first step. Yet another use for Dawn!

Post by **JimBee** » 25 Jun 2016, 07:39

Also, there did seem to be an accumulation of green dye around the low pressure filler port, so I'll also replace that valve core. The fun begins.

Pezgoon · Post by **Pezgoon** » 25 Jun 2016, 19:19

Along these lines, I got a Volvo thats been sitting for the last few years and of course there's no pressure in the ac system, ac also doesn't cycle. So just curious how does filling it with compressed air go? Does one have to worry about adding in lubricant if its been longer than the op's fill, should the ac be jumped to fill the system with compressed air? If I can do testing at home it would be best being unemployed and no money for a shop yo help me with this. I am pretty sure the evap is bad but some of the lines look pretty rusted and may not hold pressure so I would rather test everything and decide if the windows will become the permanent ac option lol

Thanks

Post by **MadeInJapan** » 25 Jun 2016, 19:57

Pretty much the cheap "fix" is just to try it- get one of the larger cans (with dye in it if they have it), with a gauge- some place like Big Lots is going to be cheaper than the auto parts store. Try to stay away from those with sealers in them- they just gunk up the system. Yes, you'll have to jump the system to get the compressor to come on if there is no gas in the system. Once it's jumped and car started and AC on full blast, recirculating, then you can undo the cap on the low pressure end (it's right in front of the ECU box), start putting gas in your system. If it holds, it holds...and your car will get cooler- if not, then you're out maybe $15-20 bucks- it's cheap diagnostics, in my opinion.