R-12 to R-134a retrofit

[87GN]

I was driving home last week and I heard this squealing noise, I didn’t know what it was until I stopped at a red light and noticed smoke pouring out from under my hood. I quickly pulled over and popped the hood and noticed that my A/C compressor clutch was glowing red :ohnoes:.

So I decided to retrofit my old R-12 system to R-134a. Especially since R-12 is about $50 a pound and my car takes about 4 lbs, also you need to be certified to even buy it. It is illegal to discharge R-12 refrigerant into the air, luckily my car had done that for me a long time ago and my AC never worked.

So I started taking apart my car:

Toasted clutch bearing:

The previous owner had replaced the accumulator/drier thinking that it would fix the A/C, but the orifice tube was covered in black crap so the compressor probably took a dump a long time ago.

I removed the compressor:

Then the Intercooler, Radiator, and Condenser:

Since I needed a new compressor anyways and the mineral oil used with R-12 is not compatible with R-134a I just decided to replace everything. The other alternatives are to flush the entire system, but in my case the new condenser, compressor and evaporator are designed to work with R-134a.

Skip forward a day, I reinstalled the condenser and radiator.

Also reinstalled the new ACDelco compressor:

I also took apart my heater box to change the evaporator core which hasn’t come yet. Now is a good time to change you heater core if it looks corroded.

Nasty evaporator core:

Now I am waiting for the evaporator and a few other things to get here before I can finish putting it together and charge it up. More pics to come…

A few extra pics I took:

[Dr.Stevil]

good job :tup: man that compressor is short. Is that an old V5 (or maybe even a scroll)?

g/l with getting it all together

[BuickGN]

my father is doing this for his new GN, but here at work we are just removing all of the old r12 and refilling it, we might just need a dryer and some o rings but thats about it.

[87GN]

Its an R4 compressor I guess GM used it on alot of 80s cars and trucks. I thought about keeping the R-12 but If it leaked out again i would be out like $200 so i decided to go with R-134a.

[BuickGN]

I used this stuff in my GN i bought at the nats a few years back, worked really well, and nothing else had to be purchased.

cant remember the name, but you did it correctly since the compressor was already shot.

[paulysplitx]

Dont forget to pull a vacum on your system once you have it all back together. That will get all the air out of along with checking for leaks. By pulling a vacum that will also help suck in the 4 lbs of 134 a you need to put in. Great write up, the car looks great!

[mechanicalmadness]

Cool. I must ask a question though. Why do you have a ratchet strap going from your alternator bracket to wherever?(frame I assume)

[Dr.Stevil]

@mechanicalmadness

Cool. I must ask a question though. Why do you have a ratchet strap going from your alternator bracket to wherever?(frame I assume)

to prevent the engine from moving too much I assume.

Kevins dad’s GN had this (pretty sure his T-Type had the same setup, or at least thought I remember seeing it in pictures)

[BuickGN]

@mechanicalmadness

Cool. I must ask a question though. Why do you have a ratchet strap going from your alternator bracket to wherever?(frame I assume)

Its for torque control, these have been known to twist the motor from the mounts.

I had one, but then i switched to poly mounts and no longer needed the tie down.

[BuickGN]

@Dr.Stevil

to prevent the engine from moving too much I assume.

Kevins dad’s GN had this (pretty sure his T-Type had the same setup, or at least thought I remember seeing it in pictures)

Most all of them have it done, unless new poly or solid mounts are installed.

[mechanicalmadness]

Ah I C. I was just wondering because of friend of mine has the same car minus the rathet strap.