Laford1986

Have a 93 and was wondering if I can Salvage Yard scrounge for the Compressor and Hoses from a R134 SC, I'll get a new Condenser. Thanks!

LeX2K

I have a car that is running R134 originally was R12 it works well. No components changed. Cooling capacity is reduced somewhat though that may be an issue for you. Can you buy R12? In California it's easy enough to find.

Margate330

From my experience nothing blows colder than R12 in cars.

RXRodger

iTrader: (2)

Wow compressors have gone up. I used to tell people don't mess around with a used compressor but now the cheapest looks like over $400. If you find one, make sure you flush all the mineral oil out and replace with PAG oil. The evaporator pressure control valve probably isn't set optimum for R134 but seems to function ok if built for an R12 system with R134 in it.

KahnBB6

iTrader: (5)

Other than that you'll be needing an R134a compatible compressor, all of the A/C system components in a 1992-2000 SC300/400/Soarer work the same if you still have R12 or if your car was/will be converted to R134a or came with R134a from the factory... with one minor exception being the rubber seals at each service point in the system. Those seals can all be changed-- it's just labor (yours or a shop's labor). The R12 compatible O-ring seals are incompatible with R134a. Consider it a full system overhaul job.

So yes you can salvage those junkyard A/C lines and re-use them if they are still in serviceable condition. Just remember that you'll need to buy a kit that upgrades all the A/C system O-ring seals to the new 134a compatible type and of course you'll need R134a compatible oil for the system (I believe Denso sells this).

RXRodger

iTrader: (2)

Actually the only thing that makes a R134 compressor compatible vs R12 is they are shipped with pag oil instead of mineral oil in the units made for R12. You can flush them and all is good, there is no difference in the compressors. And I have converted many systems and yes it is best to change orings where you can or have broken the connection but it’s not imperative. Not disagreeing but no need to change every connection if you haven’t broken it loose.

KahnBB6

iTrader: (5)

Roger, thank you for bringing your expertise into this thread! Your A/C knowledge exceeds mine and I learned something new I was not aware that it wasn't required to change *every* o-ring in the system as I'd been taught. Same with the compressor-- I was under the impression that internally the ones used for R12 were a little different from the ones sent out for R134 applications, which apparently is not the case at all.

Not having to replace the entire compressor or every o-ring makes converting to R134a MUCH easier! Then the same test dye can be added to the system when adding the new PAG oil and R134a to see *IF* there are any leaking o-rings which can be replaced by the newer types, correct?

RXRodger

iTrader: (2)

Yeah a change to R134 should require a good flush, change out the receiver/dryer, add some dye as you note, recharge it with R134. It’s never perfect when you make this change, the cooling is never quite as good with 134 as you had with R12. The one question I have had specifically with these cars is what is the pressure setting with the evaporator pressure control valve on one gas vs the other. I am not sure how to answer that without more info. That valve is something Toyota used in these systems and is not something you see in a typical automotive system. It’s just another refinement to these cars that makes it just a little better.

Bimmerbill

Roger,
When I bought my '93 sc300 several years back and at that time I was calling on shops and they ALL stated that it would be in my best interest to use the factory valve. Boy was it expensive even with my 20% discount. I just wonder if anyone had luck with the aftermarket valves. I replaced my whole system with OEM and was able to get a huge discount on everything except the valve which came from Lexus.
Bill

RXRodger

iTrader: (2)

Hey Bill, hope all is good in south Alabama. There are two “valves” in these systems. First is the expansion valve which gives you your pressure drop to enter your evaporator. Every system has these in some manner, GM always used an orifice tube but most uses an expansion valve. The second “valve” which appears to be a pressure regulator and is downstream of the evaporator. Toyota calls this an evaporative pressure control valve I think. I have never seen these before so maybe they are in a lot of later model cars which I have never worked on. It appears to me this gives a constant back pressure to the evaporator to make your gas work at peak efficiency, but just a guess looking from the outside. So the two questions would be one did you have it changed or the expansion valve? The second question is more broad being did Toyota supply the epcv at different settings for R12 and R134? Not sure how we would get that answer.

Bimmerbill

Roger,
Have been out of town for a few days and running late answering my mail. The valve I had replaced was the second one and with my 20% off at the dealer here in Mobile was over $500.00. That was why I was asking if anyone had used an aftermarket one and if they had good luck with it. Would love to know.
Bill

Laford1986

What are the sizes of the Adapters I need? I ordered adapters from Amazon and the Low side fits but the High side is the same as the Low side so it was too big...
Any help would be greatly appreciated... Ok

RXRodger

iTrader: (2)

I would suggest going to a carquest or oreilly's and have them help get the correct adapter.