98 S70, air conditioner not working :(

Post by **theWIFES_S70** » 24 Jul 2016, 11:07

Hey all, I put in one and a half cans of R-134a about two months ago and the A/C was blowing nice and cold. Yesterday we go to turn on the A/C (it's about a hundred in the sun here in Queens) and we get barely cool air. I remember that the last time we used the A/C that big cylinder thing near the compressor had a lot of condensation on it. Yesterday, it was bone dry.

We had to borrow a car for our drive because the wife really needs her A/C.

What are the steps to take now?

Post by **JRL** » 24 Jul 2016, 11:18

Oh... the usual fix will cost you close to 2K in today's dollars, that's TWO THOUSAND dollars! (retail)
On these cars the A/C evaporator goes bad, (faulty design), this is a 10 hour (flat rate) job to replace it plus a couple of hundred in parts plus a freon refill, etc.
It's a pretty daunting job even for a shadetree mechanic as the ENTIRE interior comes out, the entire dash, console, etc to get at it.

To be 100% sure fill it again but use DYE then check for leaks with a black light.
You may be lucky and the dryer may indeed be rusted out and nothing else is bad but to go from cold to nothing in 24 hours shows you have a very substantial leak. Check the dryer first, if it has an obvious leak, take the plunge, install a new one (cheap), fill and try again!
(If you can't see a leak then it's definitely the evaporator because you can't see anything with a blacklight with the dash assembled).
It usually has to be replaced every 6 to 8 years on these cars

Post by **theWIFES_S70** » 24 Jul 2016, 11:33

Sigh... Man, this car will be the death of me!

Thanks JRL, I appreciate you getting back to me. Just so I'm clear, going from bone chilling cold two months ago (and at least seven time in that time) to barely cool air points to a leak somewhere right? Not a clutch gap issue? I'm just trying to get mentally prepared for this!

Post by **cuhfs** » 24 Jul 2016, 11:43

I don't think you can rule out clutch gap. It will also cause the cold air to quit.

Post by **JRL** » 24 Jul 2016, 12:09

I doubt it
The clutch gap issue occurs after the AC has been on for a while not at start up.
As I said, start with the basics. You said the dryer looked bad the last time you saw it, well, replace that and fill (with some DYE) and see what happens.
If it still gets warm soon then either you do it or take it to a mechanic who does AC work and has the proper black light to look for the dye and remember, if you can't see any dye but it's now not cooling, 99% of the time it's a bad evaporator.
As for the clutch gap, it's pretty easy to open the hood to see if the compressor engages. You check that immediately after filling up because once the R134 leaks out, the compressor won't engage if the system is empty!

Post by **theWIFES_S70** » 24 Jul 2016, 12:31

The wife just drove the car to the gym. Told her to cycle the A/C on and off twice. She only drove for about twenty minutes. And when she parked, she said the car was "cooler" than yesterday. But not cold. So there's wimpy "cool" air coming out of the vents...

Post by **abscate** » 24 Jul 2016, 12:51

The good news the dash out repair is stupid work - I say that because even I can do it.

ITs just unbolt and unscrew. The electrical connectors are well made and unique so you can't get caught in wiring hell..

When you ready, I have the vacuum pump and gauges to pump down and test out - do you have a garage you can work in?

Post by **theWIFES_S70** » 24 Jul 2016, 13:24

It certainly looks like stupid work... Will probably contribute to quite a few more squeaks, too!

I don't have a garage, Steve. Only a driveway.

But, in that driveway I've been able to do everything I've done to this car thus far!

Just so I can prep for this. Parts needed:
- A/C Accumulator,
- A/C Evaporator Core,
- A/C Expansion Valve,
- appropriate PAG oil,
- a bunch of washers, and
- refrigerant.

Right?

Post by **JimBee** » 24 Jul 2016, 16:56

watch out for the "footnote". My compressor locked up as I was adding r134. A couple of people have since told me that you can easily hydrolock the compressor if you add liquid freon, too much, too fast, instead of just getting the gaseous form in there. That's apparently a footnote in a Volvo manual. How do you tell? I don't think you can, so as a precaution you just spurt a tiny bit at a time into the system. I think there's more to learn about that....

Post by **Ozark Lee** » 24 Jul 2016, 17:56

I would get a gauge on it before I started tearing the dash out. There are the usual guesses but they may or may not really be the problem. I just assumed that the evaporator was bad on my son's car and pulled the dash and changed the evaporator only to find that it really wasn't leaking. The leak was a rust hole in the accumulator. A can of 134A with some UV dye will potentially let you confirm the leak location if the system has a low charge. In many cases you can't really see an evaporator leak since it tends to happen on the edges and you can't really see the edges while it is in place.

...Lee