have you already changed the oil in the pump,,added a new dryer and office for the 134?
how hot is it where you are...the ambient tempeture?
after you have dried the system with your vacuum
lets not worry about the high side.....sense the 134=more than the r12..i cant really give an ounce amount...lets add the 134 until the low side holds between 32 and 50 psi..don't go over 50psi at this high of ambient tempeture...it should be fine
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