My nice thick Bentley manual for the 240 has apparently become politically correct as all it has to say about the A/C system is that one should see a professional.
I would like to do as much of the diagnosis of the non-working A/C on our 1993 240 myself as possible. I'm a very experienced DIY mechanic and I do have a simple A/C pressure gauge, DVM, etc.
Perhaps someone can point me to a good how-to diagnostics write-up on the 'net somewhere???? Please :).
TIA for any help! John
John,
You might be surprised how much experienced DIY knowledge you can get from this group. Can you give some description on your non-working A/C condition?
E.g., does blower motor work? With the car parked, motor running, hood up and you standing over the engine bay, can you hear the thermostat click the compressor clutch on and off while the temperature control is set to a medium temperature? Is the accumulator/drier "sweating" when the A/C is turned on? Can you see two puddles of water dripping on the ground near the front of the tranny tunnel? Etc., etc. I think you will find it hard to get A/C manuals or 'net literature specific to Volvos A/C.
Good questions Pat.
The blower motor works fine as does the heat and all other hvac controls.
The symptom is that when I press the switch to turn on air conditioning, nothing different happens at all. No sound of the compressor kicking in, etc. The blue indicator light comes on, but that is all that happens!
John
First thing to check is the charge, try bypassing the pressostat on the receiver/dryer, if the compressor kicks in then check the pressure. Don't run it for more than a second or two until you know there's something in it.
Thanks. I will start by putting my A/C pressure gauge on it to see if there is anything in the system.
John
I have a 1987 740 that I bought this Spring. It was still the old R12 system and all I knew was that the system had no charge, the hose from the Drier to the Compressor was rubbed thin, and the previous owner only knew he had a "hole in one of the hoses."
I spent like $120 from FCP Groton to buy an R134 conversion kit. I spent the extra $20 for an automatic expansion valve (provides better cooling) and I picked up a hose for $30. I also paid $10 for a complete O-ring kit.
I went to AutoZone and used their free loaner program for a vacuum pump and hoses. When I was ready, I made sure my system was completely de-pressurized (I didn't release any freon into the air, I knew it had all leaked out, but used a tire pressure gauge on the drier to be sure).
moisture/debris from entering lines.
I pulled the condensor and flushed it with A/C flush and compressed air. I pulled the compressor (do not flush this) and emptied the old oil out and refilled it with the entire bottle of new oil from the conversion kit. (6.5 ounces I think). Don't put oil in the drier if you fill the compressor.
I re-installed the compressor and condensor with new O-rings, put in the new expansion valve, replaced my bad hose and used new O-rings, and finally installed my new drier last. Install the drier last to prevent unnecessary exposure to air. The drier is chemically lined.
Once everything was re-assembled with new O-rings, I pulled a vacuum for 1.5 hours. I then filled the system with 3.2 cans of standard R134 and she has been working well for the last month since I've done the work.
I wish I would have flushed the evaporator, but people have mixed opinions on the need.
Here is the guide I used:
Jamie
John Horner wrote:
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