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94 850, R134a..I can find the suction side port, but where is the high side port? Also, I have a hinky low pressure valve that needs replacing, will I need to evacuate the AC system, or will I be lucky enough to find the switch isolated somehow from the system?
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There is no high pressure side on these cars...guess a safety issue. They didn't include one. What's wrong with the low pressure valve? I'd say evacuate your system if you've got to replace the valve itself, but once air is in the dryer it will soak up any moisture...might want to replace it anyway. If the valve isn't closing properly, perhaps a previous owner used the sealing type of gas. It's known to gunk up the system and cause such problems. Remember that if you let all of the gas out, you're going to have to add oil to the system. I believe it's 2 oz. to the dryer if you replace it. Also, while I was at it, I'd replace all the seals and 0-rings, making sure to oil them as you instal. Good luck.
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1998 S70 T5 Emarald Green Metallic, 2004 V70 2.5T Ruby Red, Previous Owner of Black '94 850 Turbo Wagon. My cars have been running so well lately they've got me worried.
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Yeah, after farting around all day chasing a bad high speed blower relay, a dead recirc switch and a few suspect grounds, I finally jumped the switch, and the AC ran..it was a bit low at 15 psi after stabilizing, but after a top up , the switch still would not let it run. A few light smacks with a hammer, and the switch let it start running. I've a new one on order.
Now about the high side port, how can you tell a bad compressor from a plugged cap tube or expansion valve? Who's to say I don't have a tired compressor, but added enough 134 to get suction up, but no pressure? Fortunately it's cooling fine, but it does limit diagnosis.
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Rare that compressors die in these cars...they do, but it's rare. Add enough gas to get pressure up to at least 35psi but no more than 40, as measured from the low pressure valve with the compressor on. Shut all your vents, except the center, put the temp on coldest/recirc. setting and aut. Then use a thermometer in the center vent. When temp is at 40degrees Fer. you're good to go. Hopefully your charge will last. If not more than a few days, you might want to repeat with some oil, to seal up 0-rings, etc., and if still your pressure doesn't hold, I would suspect a leaking evaporator. The compressor won't cycle on at all until there's enough gas in the system. You figured out how to jump start it. With enough gas and good switch you shouldn't have to do this at all. The other issue is the clutch in the compressor. Sometimes the gap gets to large. There's a thread here somewhere (do a search for it...it's here, I swear) that tells you how to take the washers out to make the clutch gap smaller so it will engage easier, if that makes any sense.
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1998 S70 T5 Emarald Green Metallic, 2004 V70 2.5T Ruby Red, Previous Owner of Black '94 850 Turbo Wagon. My cars have been running so well lately they've got me worried.
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Aye, it's rare but they fail. Same one in a Passat (Sanden) On that one I wasted my time adjusting the air gap in the clutch, only to find teh clutch wasn't slipping, the pump was gone. She's cool now, but I expect the LP valve to stick again.
This AC system is not as reliable as everything else on my car. Last year it was the switch on the dash, this year it was the compressor relay, then this, and also the high speed blower fan relay. The rest of the car has been rock solid, aside from the front anti-sway bar end links.
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yeah, I know what you mean by endlinks...I ended up with IPD's heavy duty endlinks. I hope they last. If not, then Quickbrick sells some that are even better, but they are expensive.
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1998 S70 T5 Emarald Green Metallic, 2004 V70 2.5T Ruby Red, Previous Owner of Black '94 850 Turbo Wagon. My cars have been running so well lately they've got me worried.
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