monarch Posted April 24, 2005 Share Posted April 24, 2005 Monarch, I dont think most people driving 14 year old cars in this forum need or want to spend a fortune for a repair when a proven method costing 90% less exists. ← But that's the Lexus owner's decision, not the mechanics decision. An honest and ethical Toyota / Lexus mechanic will inform the customer they need to decide whether or not they want a high quality R12 to R134a conversion using factory approved procedures and parts or low quality conversion using Autozone parts and procedures, "hardware store O-rings" and such. A honest and ethical Toyota / Lexus mechanic would also inform the customer that not converting and sticking with R12 is the lowest cost and highest quality approach of all. Quote Link to comment Share on other sites More sharing options...
johnw991 Posted July 10, 2005 Share Posted July 10, 2005 Do I add the R12 when the engine and A/C are running? Quote Link to comment Share on other sites More sharing options...
sha4000 Posted July 10, 2005 Share Posted July 10, 2005 Do I add the R12 when the engine and A/C are running? ← hook the can up to the lowside with the car off thenturn it on and place the a/c at its coldest Quote Link to comment Share on other sites More sharing options...
monarch Posted July 11, 2005 Share Posted July 11, 2005 Like sha4000 said, hook the can up to a low side fitting (fitting with a black colored cap) then turn the handle of the can tap valve counterclockwise to release refrigerant into the system. However, not hardly any refrigerant gas will flow into the system until you turn the engine on and turn the AC on. As the refrigerant flows into the system the can of R12 will get cold. That's a good sign the refrigerant gas is flowing. It might take 5 minutes for most of the can's gas to flow into the system. Be carefull to keep the can upright, never on its side or upsidedown because you want to charge refrigerant gas into the system, not liquid refrigerant which could damage the compressor. Now if it seems the the can is not emptying, then immerse it in a small pan or large glass of water (water temp about 100 degrees) Don't use scalding hot water because that might generate enough pressure inside the can to make it leak or explode causing serious injury. It's highly recommended to wear eye protection because you could go blind if liquid refrigerant somehow got into your eyes. The temperature of liquid R12 is about -20 degrees below zero F. Quote Link to comment Share on other sites More sharing options...
Zim Posted August 4, 2005 Share Posted August 4, 2005 Does 94 LS also use R12? Also one more question.... I think my car is cooling like average, but I've never charged the AC system in 7 years that I've owned it. It has ~230k miles. Do you think I should add a can or 2 just incase....maybe the AC is not cooling to the full potential right now and adding a bit more might help? ← The '93 on up models use R134a refrigerant. It's possible that your system is slightly low on R134a after 11 years, but if the cooling still seems good then it might need only 1/2 of a can. When the AC controls are set for maximum cooling, the center dash outlet temperatures of factory original R134a systems should be around 35-42 degrees F. If they are higher then it's a sign the system is at least a bit low on R134a. The most accurate way to measure the refrigerant level is to follow the procedure described in the factory repair manual. This involves locating the refrigerant sight glass and checking it for the presense of a stream of bubbles when the AC system is running and set for cooling. Alot of bubbles indicates too little refrigerant. But if the sight glass is mostly free of bubbles the system is either properly charged or overcharged. When properly charged, the sight glass will briefly become foamy for a second or two when the AC system is shut off. If overcharged the sight glass with stay free of bubbles even after the AC system is shut off. ← Have a 94 SC400 with R134. Seems to be low on freon - at 95 deg outside temp the vents are ~88 deg. At 82 deg outside the center vents are 66 deg. The clutch seems to work properly. Two questions - where is the sight glass you mention, and what are the freon pressure range specs? Is it best to go by filling the freon until the center temp is ~35-40 deg or should I use psi specs? I am concerned about overfilling or overpressurizing and damaging something. Thanks Zim Quote Link to comment Share on other sites More sharing options...
Zim Posted August 4, 2005 Share Posted August 4, 2005 Look I live in Bullhead City Az, It gets to 130% in the shade in July! I have 3 cars. 84 Saab, 89 Bronco, and 91 LS 400.Ford and Saab have been conveted over to 134A. If and when the LS needs Freon, it to will be conveted. Saab has over 30,000 miles running the AC with 134A! Did both cars myself. Kit and coolant was under $50.00. Is easy DIY but you must first have all leaks fixed!, then have system completly vacumed. Then ad the new 134A. Do not replace one for one. If you replace R12 with the same amount of 134A, system will be over filled and not work as well. With 134A you need about 20% less. So use a hose with a gadge on it, and refill by the gadge!. Both my Saab and Truck, cool just as good with 134A as they did with r-12. But that is becouse I did it right! Also no long term harm to system if you do it right. Use a kit that comes with the 134A that already has the oil in it. Folks mess up and do not put in the stuff with the oil, then the system will not last. ← I have the hose and gauge for the freon - but do not know what the pressure range is for a fully charged system. Do you know the range? Thanks Zim 94 SC400 140k Quote Link to comment Share on other sites More sharing options...
Zim Posted August 4, 2005 Share Posted August 4, 2005 Look I live in Bullhead City Az, It gets to 130% in the shade in July! I have 3 cars. 84 Saab, 89 Bronco, and 91 LS 400.Ford and Saab have been conveted over to 134A. If and when the LS needs Freon, it to will be conveted. Saab has over 30,000 miles running the AC with 134A! Did both cars myself. Kit and coolant was under $50.00. Is easy DIY but you must first have all leaks fixed!, then have system completly vacumed. Then ad the new 134A. Do not replace one for one. If you replace R12 with the same amount of 134A, system will be over filled and not work as well. With 134A you need about 20% less. So use a hose with a gadge on it, and refill by the gadge!. Both my Saab and Truck, cool just as good with 134A as they did with r-12. But that is becouse I did it right! Also no long term harm to system if you do it right. Use a kit that comes with the 134A that already has the oil in it. Folks mess up and do not put in the stuff with the oil, then the system will not last. ← I have the hose and gauge for the freon - but do not know what the pressure range is for a fully charged system. Do you know the range? Thanks Zim 94 SC400 140k Quote Link to comment Share on other sites More sharing options...
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