a1parrothead

Just finished repairs on A/C system. The compressor label is no longer readable. I cannot find any info in any of my manuals or books on how much R-134 I should put in it. Help!! I know it should be about 75% to 85% of its capacity, but do not know its capacity??
Any info would be great.

zwede

3 cans (36 oz) is what worked best on my '71.

Milest

I used 42oz (3 1/2 cans). I got this information from the book on Corvette air conditioning (sorry, forgot name). Mine blows cold.

vert2go89

i would think you would be under 2.5 lbs but the best way is to watch gages and pressures to be really safe.you put to much in and you will lock up the compressor.ps i hope you changed your drier and orifice tube.
wave on \ ////

bn7035

I used 3 cans and the small can of oil in my 81. Temps have been cold all summer long in 100 degree heat! :D If you put too much in the system is not as effiecient and will not get as cold as it should.

Smokehouse69

A buddy of mine just did the conversion on his 79, he used 3 cans and a can of MaxCool. He added the MaxCool several days after the conversion, and immeadiately noticed an increase in cooling (down 5 degrees at the center vents, same outside temp) , and a quiter compressor.
He told me that before the MaxCool the compressor really drug his engine down to the point that he had trouble keeping it idling in drive. After he put in the MaxCool he said he can barely tell when the compressor is on.
I wish I could find some of this stuff for R-12 systems! Mine cools pretty good, but I wouldn't mind a few degrees cooler.

chevyman

Is it safe to say then you guys put three cans of 134, one can of oil and another can of max cool. Wow. Could someone that used a gage clarify this. I put two can of 134,one can of oil and a can of maxcool and my hose blew in a week. I thought I put two much but now I dont know if my hose was just weak.

Larry B.

I don't think all systems react the same, as to amount.. My 69 (POA and expansion valve system) works best with low side pressure around 27-28psi. That is only about 2 1/2 twelve oz. cans of R134a. It cools very good and I have hd no trouble.

bn7035

Chevyman, I'll try to explain how much I put in a little better. Remember that I was certified as a jack of all trades and master of none.............. I put all most 3 12oz cans fo R-134A and a 4ozs(not sure but one of those little cans). I used on of those cheap pencil type guages and the reading was in the acceptable range. Mine is an 81. I would think that 2 1/2 cans of R134A would not build enough head pressure to blow a hose. I would tend to believe that the hose was weak due to aging. Remember that is my opinion and I do not know much about A/C systems and hopefully someone that knows something about A/C will reply.

red_z06

Here is the list I found.

https://www.acpartshouse.com/refrige...ties/chevrolet

20mercury

Same here on my 76, I added 3 cans of 12oz of 134a and got 25psig on the low, 225 on the high, 56f out the center vent, 90f ambient, relative humidity ?? in Louisiana; but is usually high with a VIR eliminator kit/A6.

I was worried about whether to put in 40 oz per recommended, but decided to go with the gauges instead as I think these readings are ok and vent cooling seems acceptable.

I am thinking you go with the gauges and start with the 36 oz of 134a and see what you get first. I saw one post that said you should be around 2.2 to 2.5 times the ambient for your high side.

Also check this site, great info:
http://www.autoacforum.com/

Hope this might help.

'75

You guys realize you answered a thread that's almost 13 years old?

hereigo

True, but I found the info helpful....