rbartick

My 1985 Helm Shop manual states that the 85 Vette uses 2.75 lbs of R12 and 6oz of mineral oil. Does that mean I am only supposed to use 6oz of R134 compatible oil? Most posts I read on the web say that people are putting 8oz or more into their cars.

I disassembled by 85's AC system, flushed the evap & condensor, and replaced the orifice (with VOV) and the accumulator. How much oil should I put into the system?

--rb--

Muffin

Put 4 oz in the compressor and rotate it at least 10 revolutions in both directions. This insures the compressor is lubricated. Then put 4 more oz in the system when you charge it with R134. This is what we did with my 85 and it works very well.

Lloyd Smale

check with your mechanic there is a new refrigerent out that doesnt require you to change anything it is a direct replacement for r12 they just put it in my 92 and it works great!!

Ron78Z&66Vette

rb...I did the exact same to my 85 a couple of weeks ago.

Actually, I think the book says 6 ounces for the compressor. If you read a little further (it took me a few times to make sense of it), it'll tell you to replace oil depending on what components your replacing. Like I said, it takes a few times to figure it out. I used eight ounces because of the way I understood the book, the sheet I got with the new compressor said to use eight ounces, and the retro-fit kit I got came with a bottle of 8 ounces of oil....so I used 8 ounces.
I put 2 into the accumulator, 2 into the evaporator, 1 into the condenser, and 3 into the compressor. You want to put the oil into the compressor suction port and rotate it with a ratchet to "prime" it like Muffin said.

rbartick

I put in 8oz of Ester Oil and used a Smart VOV. I pulled 30" of vacuum for about 45 minutes and then charged 3 12oz cans of R134a. The car blows cold air out of the vents. It is certainly blowing as cold as my late model R134a Jeep Grand Cherokee. I am pretty sure it is blowing about as cold as it did with R12.

--rb--

DON M

I can't give you a specific amount BUT, don't put in too much.
From my experiance in commercial A/C work I know that excessive oil charge tends to migrate to the evaporator (cold coil) and reduce the eficiency. When you change over to R134a there is always some oil out in the system, as oil travels around with the refrigerant. Then you add the recommended compressor oil charge and you are an ounce or two over. Follow the manufacturers guide lines. I think the GM amount is the total system charge. Change over kit manufactuerers "should allow for the extra oil in the system.
Don

SouthernSon

Take it to the shop when assembled. The shop must flush it and put a vacuum on it. The vacuum removes all moisture. When elements of system are exposed to air moisture enters the system. As I said, a shop's vacuum on system will get rid of the moisture. Otherwise, the 134a will react with the moisture, become corrosive and your compressor will expire within a short period of time. The shop then puts in the required amount of oil (ester) from a reservoir on their system that keeps the system sealed during the process and then puts in the 134a. check out www.id-usa.com

rbartick

>Take it to the shop when assembled.
>The shop must flush it and put a
>vacuum on it. The vacuum removes all >moisture.

Did you read my post? Two posts above yours I said "I pulled 30" of vacuum for about 45 minutes and then charged 3 12oz cans of R134a."

--rb--

Hendej

I missed something. Last I heard, your VOV didn't fit (too long). What was the fix? Did you use the standard evap mount GM part?

rbartick

>Last I heard, your VOV didn't
>fit (too long).

I was wrong, the VOV fit perfectly. I used the standard evap mount GM part. It was sunny and > 85 F degrees over the weekend here on the right coast and my wife asked me to turn down the AC because it was too cold. R134a with the VOV works well enough for us.

--rb--

Romeo Barrera

Told ya you'd have no problems with the VOV