new compressor question.

[firebird_1252]

well i'm finaly starting to get my gn up and running again. it needs a new ac compressor. my car untill i let out the ac was still r12.  when the new compressor goes in can i just put r134a?

[87natty]

I don't think so. I don't know much about AC, but I think you'll have to flush out all the old R12 and then replace all your seals, as the 134a molecules are smaller than the R12 ones and leak through. They sell conversion kits at auto parts stores, but I've never used one.

Mine is an R12 car too, made in Feb of 1987, and I was told all 87 cars had 134a in them? Meh, my AC is dry and it's fucking hot in Cali.

[Steve Wood]

there are lotsa instructions for doing the swap.  Best to get all the oil out of the entire system and replace it with the oil made for 134A, put a new can on it, and replace the orifice tube with one made for 134A.....I suggest using the variable orifice tube as I find they cool better at idle.

[firebird_1252]

Mine is an R12 car too, made in Feb of 1987, and I was told all 87 cars had 134a in them? Meh, my AC is dry and it's fucking hot in Cali.

mine was 34.5* out of the vents

[firebird_1252]

steve, do you recommend swaping the evaporator air dryer and everything?

[Steve Wood]

that is what I called the can...and yes

[ULYCYC]

What's wrong with the old compressor?

[straycat990]

I don't think so. I don't know much about AC, but I think you'll have to flush out all the old R12 and then replace all your seals, as the 134a molecules are smaller than the R12 ones and leak through. They sell conversion kits at auto parts stores, but I've never used one.

Mine is an R12 car too, made in Feb of 1987, and I was told all 87 cars had 134a in them? Meh, my AC is dry and it's fucking hot in Cali.

Look for a product called freeze 12 it is compatible with r12 oil and does not require a license to purchase.  You will need to vac out all the r12 in the system.
I can get it in Va at the local NAPA store.  It worked great in my Limited and GN.

[ULYCYC]

I used a product called Autofrost. It's safer then Freeze12. Been in a few cars I did for years. I did my Park ave with it 4-5 years ago. Haven't touched it since and still gets duct temps in the high 30's

[firebird_1252]

ed the old compressor is locking up everynow and then.  i also need all the o-rings changed. i'm going to look in to the autofrost. how much do is it ed?

[SuperSix]

I hear our condensers aren't great for R134a, and to get the most out of an r134a system - you should replace the condenser that is in front of the radiator. And the dual fan set up won't hurt at all.

[SuperSix]

And if you do replace the compressor - replace the dryer (accumulator) and *all* O-rings in the system. BEFORE you vacuum it down and recharge.

[Recklessrob]

All GN's came with R-12. R-134a wasn't introduced until approx. 1993.
Avoid the aftermarket replacement refridgerants because many are highly flamable.
Like Steve said, use a new can, and a variable rate orifice tube. (both are available at NAPA) Many will say to use Ester oil when retrofitting, but from my personal experience PAG oil seems to work better. Also as Brian has said, it is recommended that you replace the old O'rings with new ones (NAPA also sells a vehicle specific kit with all the required O'rings and a few extra..in case you drop one etc...)

This isn't necessary, but it worked for me:
My original compressor was junk when I bought the car. At the time I was short on cash and my boss had given me a good compressor from a '95 S-10 with a 4.3.
The compressor physically bolted in with the use of a shorter belt (due to it having a smaller pulley) and an adaptor kit to get the manifold to attach to the rear of the compressor. ( I used the left over parts that came with a new compressor )
The only other thing I had to change was the electrical connector. (which was also available at NAPA) Don't forget to keep the diode when replacing the connector.
I actually kept the OE connector and wired the new one parallel.
Since the S-10 compressor was intended for R-134a it performs excellent in my car.

[Top Speed]

Good advice Rob!