a/c on 92 rodeo

[infamouspdp]

i want to change over my 92 to 134.i used the kits several times before on other cars and trucks,mainly chevy/ford.the compressor seems to be engaging when you push the button.the engine idles up anyway.which line should be the low side?the larger line on the pass. side of the engine?it's a 2.6 manual transmission by the way.how much pressure should it read when fully charged?it blows no cool air at all,but i'm getting pressure when i press on the valve core on the line.thanks for any input.

[suvguy]

Explain how you went about retrofitting from R12 to R134a. What all did you do before charging with 134a? How did you charge with the new refrigerant?

suvguy

[infamouspdp]

i haven't changed it yet.i just wanted to know how much pressure i should have and the best way to do it.

[suvguy]

Originally Posted by infamouspdp

i haven't changed it yet.i just wanted to know how much pressure i should have and the best way to do it.

The mineral oil used with R12 is not compatible with the PAG and PAO oils used for R134a. A thorough cleaning and flushing of the system must be done. If you want your R134a charge to last you need to buy 134a compatible hose repalcements or have a set made. All o-rings need to be changed and your comressor needs to be be completely drained of oil and then flushed clean, or replaced with a newer unit with the proper internal o-rings and seals. If yor system uses an orifice tube, a new one for R134a should be installed for best performance. After all that and your ready for charging, vacuum the system down to less than 500 microns for thrity minutes and then check for leaks. If no leaks, continue on for another 30-60 minutes or more. For proper charge, it is best to figure out the weight of refrigerant required. Judging by pressures alone will get you in the ball park, but will not get you right. Low side is most, if not always, the larger pipe and is usually insulated. Ideal pressures should be between 35-45 and 220-250 psi at 77-80*F. Most service manuals will have a temperature/pressure chart for R134a.

Lots of details left out, but that's the canned version.

[MrMGA]

Here's another option. Go to Wal-Mart and buy an Interdynamics "EZ-Chill Recharging and Retrofit Kit" for about $30. It says on the box "Convert an R-12 A/C system to R-134a in 4 easy steps." I bought the kit for recharging an existing R-134a system, not for retrofitting an R-12 system, so I don't know how "easy" it really is. (For one thing, they assume you have already evacuated the R-12.) The kit comes with a CD containing several "how-to" videos.

Also, check out the Interdynamics web site at www.id-usa.com. They have a bunch of information on recharging and retrofitting automotive A/C systems.