ac recharge/conversion question
Le Mans Master
Joined: Jun 2006
Posts: 6,400
Likes: 1,226
From: Tampa Florida
capecorvette I do not know the specifics of your 1979's A/C system, however my 70 A/C has an expansion valve and the line connecting to the expansion valve coming from the condenser has a small metal screen/filter in the expansion valve connection. If a dryers desiccant bag/container has leaked desiccant it will travel to the expansion valve and stop the flow of R12 or R134. It happened to my 70 in 1988. GM dealership mechanics could not find the problem, I did by reading my service manual.
Burning Brakes
Joined: Apr 2008
Posts: 945
Likes: 1
The gauge set looks ok, not sure about the pump, though. I have never used on that small before.
R134 may come with lubricant, its ok to top off, but to replace componants and recharge, I wouldn't do it myself.
If you are just doing the dryer and expansion valve, its probably ok.
If you are converting from R12 to R134a you need to change all the oil in the system, otherwise you are asking for trouble. The older R12 oil will not be compatable with the 134a. You also have to be careful, because some of the older componants in the system may not be compatable either.
You also must have gauges to get the 134a charge right, because the site glass alone will not be a good indicator for the 134a.
R134 may come with lubricant, its ok to top off, but to replace componants and recharge, I wouldn't do it myself.
If you are just doing the dryer and expansion valve, its probably ok.
If you are converting from R12 to R134a you need to change all the oil in the system, otherwise you are asking for trouble. The older R12 oil will not be compatable with the 134a. You also have to be careful, because some of the older componants in the system may not be compatable either.
You also must have gauges to get the 134a charge right, because the site glass alone will not be a good indicator for the 134a.
Pro
Joined: Nov 2002
Posts: 599
Likes: 16
From: vista CA
Second time in this post saw about the blue Ford orifice tube rather than the white. What is the reasoning for this? The magazine article on conversion looked like a regualr white tube. I have also heard it better to use a variable orifice tube?
