For r134 to work, you MUST evacuate/pull a vacuum first.  You could add cans
all day, but if you have air or moisture in your system it won't work well.
Also, having too much r134 in your system can bind it up and reduce your
cooling.  Buy, rent, or borrow a set of gauges and a vacuum pump, and do it
right.

 <A HREF="http://gti16v.org/tb879503.htm">Technical Bulletin A/C System, Retrofitting R-12 to R-134a</A>
( <A HREF="http://gti16v.org/tb879503.htm">http://gti16v.org/tb879503.htm</A> ) tells you how much you need and how to do
it.

Bill Marshall
85 GL Tiico "Pandora's Box"
Aurora, IL