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1993 Volvo 240 AC Lost Its Cool: Question

Michael92

Michael92

Member
Joined
Mar 24, 2018
Hi There TB,


I recharged the AC in my 1993 Volvo 240 the other day. New dryer, and changed most of the o-rings in the lines. Changed the orifice tube before recharging as well. Was working fine for 3 weeks or so, and today I noticed the air temp today is rather nuetral, and the pressure fan kicks on almost immediately after turning the compressor on.

Bought a UV light and Yellow glasses to see if there are any leaks I missed. Any ideas why the AC would blow warm with no known leaks? Could the Orifice tube be clogged and that is what is creating the high pressure and causing the electric fan to kick on?

Any insights?
 
Do you have a gauge set or at least buy a can of R134a with a pressure gauge to charge the system? Be nice to know, first, if it is loss of gas.

After that gotta hunt for the leak. Dye or 'sniffer'.
 
Did you draw a vacuum on the system first? Not only is it good to boil the moisture out of the system, but it will tell you if there is a leak.
 
I had it professionally recharged. They hooked it up to a snap on machine and we put the dye in it also. I havent seen any oily residue on any of the fittings yet, but I ordered the yellow glasses and the uv flashlight to see if I can spot a leak I missed. If it has a leak, would that cause the electric fan to turn on almost immediately?
 
Hard to say without checking, but you probably still have a leak. Check your condenser. Rocks can fly up and puncture it. Did you ever get an odd smell in the car? Evaporators can leak too, but they're tough to check visually.
 
Update: I opened the cap on the low side charge port and I have a steady leak from the valve and some dye and oil sprayed out. It should not be leaking from that valve, right?
 
It should not.

Got a valve tool? Any auto parts store will have them for a couple bucks. Tighten the stem down and see what happens.

If still leaking you are going to have to replace the valve stem which will let out all the gas.

Not an unusual leak point.
 
I took it to a good mechanic and he unintentionally overfilled it. It calls for 1.63 lbs of refridgerent and I remember him stating to me that he was putting slightly over 2 lbs in. It has a steady hiss from the refrigerent leaking out of the shrader valve with the cap off. I assume it was because the system was overfilled by 25%.

I hope it didn't damage the compressor as I put in a really nice used OEM R134a one. The compressor spins freely and didnt make any noise being spun slowly by hand. I hope the mechanic resolves it reasonably and hopefully with little charge. I am going to change the shrader valve and put a new orfice tube in it at the very least. Thoughts?
 
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I wouldn't worry about it. It sounds like you need a better mechanic though. lol Have you thought about filling it yourself? Gauges and vacuum pumps are currently on sale at Harbor Freight! When the tool is hooked on to the quick connects, the valve should only be turned far enough to start seeing pressure on the gauges. If you bottom them out, you run the risk of damaging the valve which is something I see on almost every AC system that's been messed with in the past.
 
volvowagoon said:
I wouldn't worry about it. It sounds like you need a better mechanic though. lol Have you thought about filling it yourself? Gauges and vacuum pumps are currently on sale at Harbor Freight! When the tool is hooked on to the quick connects, the valve should only be turned far enough to start seeing pressure on the gauges. If you bottom them out, you run the risk of damaging the valve which is something I see on almost every AC system that's been messed with in the past.
Click to expand...

I looked into a bit and Oriellys even has the gauge set and the vacuum pump as a loaner tool so I will evac and fill it myself. Thanks for the heads up, I will open the valves less than fully open and thank you for bringing up the idea of doing it myself. Haha give a man a fish and he eats for a day, teach a man to fish he eats for a lifetime. That analogy applies here
 
Michael92 said:
I looked into a bit and Oriellys even has the gauge set and the vacuum pump as a loaner tool so I will evac and fill it myself. Thanks for the heads up, I will open the valves less than fully open and thank you for bringing up the idea of doing it myself. Haha give a man a fish and he eats for a day, teach a man to fish he eats for a lifetime. That analogy applies here
Click to expand...

Oh cool! I didn't know that those tools were provided as loaners. I would also not worry too much about the refrigerant weight as much as system pressure. I still look at both, but this chart will help you find out if you really need to shove more in there or not.
v4e1E9W.jpg
 
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Sad news. I am almost positive that having the AC overcharged damaged the Compressor. I opened the AC lines and there is metal shavings on the orfice tube. So, I think I will have to replace some parts
 
Michael92 said:
Sad news. I am almost positive that having the AC overcharged damaged the Compressor. I opened the AC lines and there is metal shavings on the orfice tube. So, I think I will have to replace some parts
Click to expand...

My Buick's orifice tube was practically clogged full of metal shavings when I replaced it, but I'm on my second year of flawless operation since then. I say replace the orifice tube, flush the system, and recharge!
 
That system has a high pressure safety switch that wouldn't allow operation if pressures raised too high, probably errant metal still is the system (or your tech over-torqued some lines...). Have the refrigerant recovered then replace both schrader valves (high side too) and vac the system for at least 45 minutes and make sure it holds vacuum for at least 30 mins afterward. Should be all good and you'll notice much better cooling when the system is topped off properly. Good luck!
 
A/C leak

I would bring it back to the shop and have them recover it. The machine will weigh how much is evacuated.

With an old car, you could have leaks anywhere, but the condenser is the first place I would look. It is in front of the radiator and takes lots of abuse from thermal cycling and exposure to the outside environment. Worst case scenario, you have a leaky evaporator core.
 
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