a/c
 

We have a 1990 suburban whose a/c is not working. We bought the conversion kit from our local parts store but I just spoke to a local a/c shop and he knows no one with the machine to clean the old R12 out of the system.

What do you all recommend to convert this truck?

Bill

Re: a/c
 

I haven't converted a truck before, but can you not use regular AC system flush? The bottled stuff you pour in the system and blow out with compressed air? I'd flush it at home and use a refrigerant that doesn't require pulling a vacuum on the system like Enviro Safe. It works, and you can do all this at home.

Re: a/c
 

I'm scratching my head over here. If you have air in the system how in the heck can it cool efficiently? I looked on their site but didn't find much info. Last time I compressed air and then let it out it wasn't giving me frostbite... I don't know but I'm a bit skeptic.

Re: a/c
 

i see this post come up time to time on forums, and there are some strict converting people who say you have to change a bunch of crap and flush the system, when i did mine in my 1990 silverado, the system was empty, i put a set of fitting adapters and filled it up with 134a freon and been fine for the past 6 years

there is a difference of how much you put in compared to the old stuff, something like 15% less or more i forgot, im sure a quick google search will show you what you want to know

Re: a/c
 

Honestly I don't know. I'm no AC expert, just a shade tree guy. A few friends tried it in their hot rods and liked it so I bought some.

Re: a/c
 

134A takes less. Usually about 10% less. I'd just use a standard flush kit and be sure to use the proper oil when you refill.

Re: a/c
 

We can buy a conversion kit locally and it looks simple enough but the problem is to vacuum out the old R12. Can't mix the 134A into existing r12 and it's illegal and not environmentally to just let it loose in the air.

No one local has the equipment anymore. Any ideas on what kind of a shop would?
Bill

Re: a/c
 

I wouldn't worry too much about a flush machine. Get a bottle of AC flush, pour some into the open system and blow it out with compressed air. Do that a few times, then take it to your favorite mechanic and let him pull a vacuum on it and fill with 134. Remove the drier and any new parts for the flush though.

Re: a/c
 

I just finished getting the A/C (both front and rear)working in my 1990 Suburban. I replaced the compressor, condenser, receiver/drier, the expansion tube. I did not replace the rear evap though. Once I got the system together, i put the vacuum pump on it and left it running for a couple hours to get all the moisture out of the system. I then left a vacuum on the system for a day and checked it to make sure there were no leaks. Then I filled it with a little of 4 lbs of R134A and now the A/C blows out sub 40 degree air out of the front and back vents.