850 Air Conditioning Woes

[sventastic]

Hey everyone, I'm hoping to gain some insight on how to tackle my non-functioning air conditioning.

I have a 1996 850R, bought it in Oct. 2016, and at that time the AC was barely working. Summer of 2017 it continued to work very weakly, just enough to stay comfortable. I noticed when the compressor clicked on, it would turn off after only 1 or 2 seconds. Fast forward to summer 2018, and the AC doesn't work at all, the compressor stopped clicking on at all, even after I got the refrigerant recharged. Fast forward again to summer 2019 and the compressor no longer clicks on at all, even after the bread clip mod to shim the compressor clutch, and I generally hate my life when driving during the day.

Since shimming the clutch, I haven't had time to think about fixing the AC but it's starting to get warm again so I'd like to start investigating and hopefully repairing the AC before summer comes along.

Am I looking at an evaporator replacement? Any other ideas?

Couple pics of the car for general enjoyment

[850 LPT]

Wow, that's a fantastic looking R, and it has 3 pedals too!

And yes, it's evaporator time.

Dirk

[sventastic]

Wow, that's a fantastic looking R, and it has 3 pedals too!

And yes, it's evaporator time.

Dirk

Thanks Dirk, 3 pedals is the way to go with these, I manual swapped it almost 2 years ago now!

What makes you sure it would be the evaporator? I'm thinking it's very possible, as the car has 266,000km and it could be original

[abscate]

You can remove the fan power module and inspect the evaporator or use a bore scope down the fresh air intake under the windshield cowl. Basically , you diagnosis the evaporator by elimination. Use some Freon/dye in the system then inspect the fittings with a black light. My semi-educated guess as to the failure modes of AC leading to leaks, ranked in descending order of probability

Evaporator
Leak at low pressure valve
Rusted out accumulator/ drier
Compressor leak
Condensor..usually from contact damage
Soft hoses...look for good ones at junkyards as some are now only available as Volvo parts and aren’t cheap.

The evap job is about 10-12 hours for a first time, and half that once you have done it. You need a couple of cheap specialty tools to get the fittings loose, and sometimes they really get jammed and you have to cut old lines and replace with used/new parts.

My gory story is here.

viewtopic.php?f=1&t=56005&hilit=1999+v70+t5&start=0

[Richard99]

You mentioned that you recharged the A/C with your A/C compressor not working. How did you do that? It usually won't take a charge unless the compressor is running. I had to jump my compressor to get the gas in last time I did it.

[850 LPT]

Wow, that's a fantastic looking R, and it has 3 pedals too!

And yes, it's evaporator time.

Dirk

Thanks Dirk, 3 pedals is the way to go with these, I manual swapped it almost 2 years ago now!

What makes you sure it would be the evaporator? I'm thinking it's very possible, as the car has 266,000km and it could be original

Remember they have a 100% failure rate. And if it's older than say 8 -10 years it's shot. The original would have been gone years ago, you must be on your second or third. That said, it's a good idea anyway to check the items on Abscates list.

Good luck, Dirk

[misha]

My ac system is original.
I maintain it preventatively every 3rd year at professional ac shop...no problems with it and ac is ice cold.

[abscate]

You can’t even buy AC on a Volvo in Siberia , Misha

[misha]

[sventastic]

You can remove the fan power module and inspect the evaporator or use a bore scope down the fresh air intake under the windshield cowl. Basically , you diagnosis the evaporator by elimination. Use some Freon/dye in the system then inspect the fittings with a black light. My semi-educated guess as to the failure modes of AC leading to leaks, ranked in descending order of probability

Evaporator
Leak at low pressure valve
Rusted out accumulator/ drier
Compressor leak
Condensor..usually from contact damage
Soft hoses...look for good ones at junkyards as some are now only available as Volvo parts and aren’t cheap.

The evap job is about 10-12 hours for a first time, and half that once you have done it. You need a couple of cheap specialty tools to get the fittings loose, and sometimes they really get jammed and you have to cut old lines and replace with used/new parts.

My gory story is here.

viewtopic.php?f=1&t=56005&hilit=1999+v70+t5&start=0

Thanks so much, I went through your thread and there was lots to learn. Those evap lines are pretty expensive so I'd definitely do my best to not have to cut and replace them... Luckily I don't live where rust ruins cars. I don't have a boroscope camera but I might just do the evaporator and hope for the best