A/c Questions

[NewGuy19]

Two summers ago when I purchased my Lexus it blew ice cold air all summer long. Then over the winter months I believe it all leaked out. The previous owner stored the Lexus in a heated garage and never drove it all winter so I think the cold temps must have cracked a seal or line somewhere <_< .

Last summer I lived without the a/c. I rode my bike every day I could to cut down on the gas bill and just rolled the windows down in the car whenever possible. But with a little extra money from the government this year :D I was looking to get my a/c fixed before the heat gets here again this summer. I've searched a lot on here and found a lot of conflicting information as to cost, effectiveness and how to do it.

I was wondering if anyone on here has any helpful information, or possibly experience in doing a conversion. From what I can gather most legitimate conversions are gonna run you $400-500 at a shop. I'd like to do the work myself if possible. Any input or guidance would be greatly appreciated.

[TA in KC]

I successfully converted my 92 LS400's R12 system to R134a with a simple conversion kit purchased from an auto parts store for around $40.

Some people call them "AC death kits", but it has been 2 years and I have never had a problem. I did, however, have a family member help me with the procedure who is a retired auto mechanic with extensive knowledge of A/C systems.

If you don't know much about air conditioning systems, or know someone who does, I suggest you have the conversion done by a professional.

[DrJfrmLA]

Two summers ago when I purchased my Lexus it blew ice cold air all summer long. Then over the winter months I believe it all leaked out. The previous owner stored the Lexus in a heated garage and never drove it all winter so I think the cold temps must have cracked a seal or line somewhere <_< .

Last summer I lived without the a/c. I rode my bike every day I could to cut down on the gas bill and just rolled the windows down in the car whenever possible. But with a little extra money from the government this year :D I was looking to get my a/c fixed before the heat gets here again this summer. I've searched a lot on here and found a lot of conflicting information as to cost, effectiveness and how to do it.

I was wondering if anyone on here has any helpful information, or possibly experience in doing a conversion. From what I can gather most legitimate conversions are gonna run you $400-500 at a shop. I'd like to do the work myself if possible. Any input or guidance would be greatly appreciated.

Have you changed the cabin filter? If you have more than 30k or so miles and you live anywhere remotely dusty, chances are the cabin filter is so clogged no air can get through if it hasn't been changed. I change my filters every 15k or so, and the air is noticeably colder after a filter change.

[1990LS400]

Have you changed the cabin filter? If you have more than 30k or so miles and you live anywhere remotely dusty, chances are the cabin filter is so clogged no air can get through if it hasn't been changed. I change my filters every 15k or so, and the air is noticeably colder after a filter change.

I owned a 90 LS for 13 1/2 years and I'm pretty sure that it didn't have a cabin filter -- I think 93 was the first year for that.

I had my 90 LS converted from R12 to R134a in about 2001 by an indie Lexus repair shop. Prices may have risen but I think I paid about $250. The shop was never able to get rid of all the leaks and a little R134a had to be added about once each year -- but at least the R134a was cheap.

When I last spoke with the current owner of my 90 LS, he was still adding R134a occasionally and the A/C was still working fine.

After conversion to R134a, the A/C still worked great. I'll never forget when four of us sat inside the 90 LS with the engine idling for about an hour on a 100 degree day in the Kansas City Royals Stadium parking lot -- the A/C was putting out enough cold air that it seemed like it could have cooled a house and the engine temperature gauge didn't budge from the it's normal reading.

[NewGuy19]

Thanks for the info guys. They didn't start using cabin filters till '93 as 1990LS400 stated. I am pretty good with a wrench and do all my own work. Well with the exception of my water pump, since I was 400 miles away from my tools when the pump went out. I'd like to try the conversion myself, however I understand I may need to take it to a shop to have them change the oil in the system thats not a big deal. I think I'll try picking up one of those conversion kits and give it a go over spring break.

Does anyone have a diagram or anything showing exactly where the seals and valves are that will need to be replaced? I'd kinda like to have a general idea before I dig into the job.

[TA in KC]

Thanks for the info guys. They didn't start using cabin filters till '93 as 1990LS400 stated. I am pretty good with a wrench and do all my own work. Well with the exception of my water pump, since I was 400 miles away from my tools when the pump went out. I'd like to try the conversion myself, however I understand I may need to take it to a shop to have them change the oil in the system thats not a big deal. I think I'll try picking up one of those conversion kits and give it a go over spring break.

Does anyone have a diagram or anything showing exactly where the seals and valves are that will need to be replaced? I'd kinda like to have a general idea before I dig into the job.

The high and low pressure ports will need to have replacement connectors installed. That is really the biggest part of the job.

You cannot replace the oil independently, or without opening up the A/C system and replacing the drier. The oil is suspended in the refrigerant. Most conversion kits come with refrigerant that is already mixed with oil.

The system should be evacuated slowly so that most of the oil will come out with it. Of course, some R-12 mineral oil will still remain in the system so it is important you choose a refrigerant/oil mix containing Ester oil...the only R-134a oil compatible with R-12 mineral oil. PAG oil and others are not compatible.