Air conditioning charge
 

Hi All,

Been a long while since I have posted anything.:rolleyes:
What is the correct way of charging the A/C system on a my 89 GT? The A/C has worked pretty good for the last 7 years I have owned it, but it is just barely cool at the vents now. I need to know for sure what port to fill and if I need to rev engine etc. I'm no expert on the subject.

Re: Air conditioning charge
 

Unless you converted to r134, your on a r12 system, it can be costly, and you cant buy r12 anymore, they have a "freeze 12" replacement, but you have to be licensed to buy it here in my state anyway.
Also, It is best to let a vaccuum pump sit on the lines, and evacuate the system, you will get ice cold a/c if you do it this way.
I recommend you convert to r134, it's not too hard, but do some research first, or you can ruin you compressor.

Re: Air conditioning charge
 

all you need to do is get all of the r12 out and replace the fittings and recharge it with r134a.thats all my work has been doing for the last 12 years..when i took the test to be certified for a/c they say u have to remove the r12 and remove all the a/c parts to get all of the oil out and then re install every thing with different seals, but thats a bunch of crap.all i have done on every conversion is remove the r12 and put fittings on and refill..do that and get the r134a from a parts store and most of them come with dye in it so if u have a leak u can pin point where it is.

Re: Air conditioning charge
 

ps if u do change it on a 70 degree day u want 30 psi on the low side and around 38 on a 90 degree day...if u put to much in the air will be hot