AC Recharge

[alternatereality54]

i have a 1992 chevy s10 tahoe and im wanting to recharge my dried out ac. do i have to replace anything in the way of parts to convert from r12 to r134a? can i just let it drain, or do i have to vacuum out the r12?

[MT-2500]

On a change over the R-12 has to be removed with a r-12 certified mechanic.

The receiver/dryer and system oil has to be changed and recto fit fittings installed to change to r-134a
Also the ac charge should be cut 10-15 %.

You might consider just staying with R-12 if system is good and no leaks.

R-134a has went way up in price.

[alternatereality54]

thanx, is it possible to a conversion without swapping any parts? i do have retro fittings

[MT-2500]

Originally Posted by alternatereality54

thanx, is it possible to a conversion without swapping any parts? i do have retro fittings

It is called a dirty retrofit.
But.
Get as much of the r-12 oil out and try adding ester oil to the system so the old r-12 oil will mix with the r-134.
And be sure to cut your charge 10-15 percent to keep high pressure down
Good Luck

[MT-2500]

Also you need to pump out all r-12 and vacuum system out.

[alternatereality54]

sweet thanks

[alternatereality54]

is the vacuum absolutely necessary for the evacuation?

[j cAT]

Originally Posted by alternatereality54

is the vacuum absolutely necessary for the evacuation?

with this question I must add that dumping R12 refrigerent into the atmosphere will get you a very large 10,ooo.oo fine..reason is this material destroys the atmosphere ...have a pro remove the R12..this then will be recycled..

when the system is being converted to R134 to do this so It will last a good amount of time you should have the system chemically cleaned also...as mentioned remove all of the R12 compressor oil...then add the ester oil of the correct amount ..then with the system closed place vacuum pump on it for 2hrs or until the vacuum holds 500 microns with pump off...this is required because the oil absorbs mositure and when under a vacuum it must BOIL OFF....

IT IS TRUE do not add the full system capacity amount of R134 because the high side pressures could go too high , if so you will damage the system componets....