9600baud

Hi I'm tired of trying to get my R12 to work with R134a so I want to just put in all the air conditioner components in for an R134 system. What would I need? I'm thinking compressor, evaporator, and condenser? Is there any other parts I should look for?

Thanks!

MooJohn

I'm kind of curious to know what issues you've had so far trying to make it work without changing hardware. I plan to do it the cheap way with just a new dryer, adapter for the low side port, and some parts-store refrigerant cans.

My car's AC has never worked since I got it. I have verified that the compressor does work so I don't mind throwing $100 at it to see if I can get it going.

LScowboyLS

● a new evaporator is unnecessary, and that is where most of the expense is (labor) unless you are changing the expansion valve, which would be the first class way to do it

● a new condenser is the most critical component to having it cool down well, as R-134a is not nearly as efficient of a refrigerant as R-12 and that efficiency has to be made up somewhere.

● new suction & discharge hoses and compressor and dryer engineered for 134a will allow the system to work reliably for a long time, without changing those two, it is a bit iffy

so to review, to do it right, you would be changing the following,

● condenser
● hoses
● compressor
● dryer
● expansion valve
● oil
● refrigerant
● charging ports

that is pretty much the entire system other than the liquid line and the evaporator! - this will cost more than your car is worth!


the cheapest route for those on a budget, and in my professional opinion, the best way to get your A/C working and working really well for a long time is: don't convert to 134a at all

R-12 is still available, and legal to charge into vehicles that had it originally, and for the tiny amount your SC or LS or GS system holds (less than 2 lbs.), the price difference between R-12 and 134a is like $20-$40 - so just fix what is actually broken or leaking, pull a very serious vacuum for several hours, and charge it up with R-12, and remember the golden rule:



the only other semi-accurate way is to watch the sight glass, adding refrigerant very slowly, stopping to watch the glass for 5 minutes at a time, and stop when you never see any more bubbles, but even that is a very rough method.

LScowboyLS

Keep in mind something, the most common place an older SC or LS A/C system fails would probably surprise the hell out of you, it's failing ECU capacitors

the tell tale sign is if your front defog light flashes about ten times when you start up the car (this is the system going into reset, due to the ECU issue)

SC400slide

iTrader: (11)

When I did a complete clean conversion from R12 to R134a all it took was new upgraded schrader valves on the H and L port, and a brand new compressor. (R12 originally, but converted it BTW). Charged it up with 134a and the A/C has been ice cold for over a year. Still is.

MooJohn

I've been banging the "get your ECU rebuilt; don't keep buying used ECUs" gong since joining CL. As a former 1st gen DSM owner (from new in 92) I'm familiar with how bad 1990s ECUs can be. It was one of the first things I did after getting my SC.

Mine has low (or no) freon in the system. I have verified that the compressor works by jumping the pressure switch. I'm willing to waste $70ish to see if it happens to work after a fill.

Joey-E

iTrader: (1)

I still use R-12 the hard part is finding where they sell it for a good price. Texas heat is not a joke.

9600baud

Thanks everyone, specially LSCowboy. I didnt think parts would cost that much, I'll run some quotes around here and update on what I endup doing.

SC400slide

iTrader: (11)

The R12-R134a conversion costed me about $50.00.

-New R12 compressor in trunk when I bought the car so no new compressor or system evacuation was needed.
-PAG oil for the compressor was only 5 bucks
-R-134 wasn't too bad...but was a chunk of the cost.
-Conversion kit from who else but Wal-Mart was only 40 or so dollars.

So all I had to do was swap out the old compressor for a new one, charge the system up, swap schrader valves with extensions on H and L ports, and everything else neccessary, (which was cheese), then my A/C was ice cold.

Best $55.00 I've ever spent.

megamax

iTrader: (9)

so heres my question. if I have a 94 sc400. and it looks like the stock low side port fits in the r154 charge bung. I heard on this thread you need an adapter??? if it fits it works right??

SC400slide

iTrader: (11)

If it fits I'd think it would work just fine. Only way to see is to try it! If it were me though, I'd just put the adapter on the l side port anyways.